Merge branch 'linus' into test
Conflicts: MAINTAINERS arch/x86/kernel/acpi/boot.c arch/x86/kernel/acpi/sleep.c drivers/acpi/Kconfig drivers/pnp/Makefile drivers/pnp/quirks.c Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Коммит
057316cc6a
1
.mailmap
1
.mailmap
|
@ -66,6 +66,7 @@ Kenneth W Chen <kenneth.w.chen@intel.com>
|
||||||
Koushik <raghavendra.koushik@neterion.com>
|
Koushik <raghavendra.koushik@neterion.com>
|
||||||
Leonid I Ananiev <leonid.i.ananiev@intel.com>
|
Leonid I Ananiev <leonid.i.ananiev@intel.com>
|
||||||
Linas Vepstas <linas@austin.ibm.com>
|
Linas Vepstas <linas@austin.ibm.com>
|
||||||
|
Mark Brown <broonie@sirena.org.uk>
|
||||||
Matthieu CASTET <castet.matthieu@free.fr>
|
Matthieu CASTET <castet.matthieu@free.fr>
|
||||||
Michael Buesch <mb@bu3sch.de>
|
Michael Buesch <mb@bu3sch.de>
|
||||||
Michael Buesch <mbuesch@freenet.de>
|
Michael Buesch <mbuesch@freenet.de>
|
||||||
|
|
12
CREDITS
12
CREDITS
|
@ -1653,14 +1653,14 @@ S: Chapel Hill, North Carolina 27514-4818
|
||||||
S: USA
|
S: USA
|
||||||
|
|
||||||
N: Dave Jones
|
N: Dave Jones
|
||||||
E: davej@codemonkey.org.uk
|
E: davej@redhat.com
|
||||||
W: http://www.codemonkey.org.uk
|
W: http://www.codemonkey.org.uk
|
||||||
D: x86 errata/setup maintenance.
|
D: Assorted VIA x86 support.
|
||||||
D: AGPGART driver.
|
D: 2.5 AGPGART overhaul.
|
||||||
D: CPUFREQ maintenance.
|
D: CPUFREQ maintenance.
|
||||||
D: Backport/Forwardport merge monkey.
|
D: Fedora kernel maintainence.
|
||||||
D: Various Janitor work.
|
D: Misc/Other.
|
||||||
S: United Kingdom
|
S: 314 Littleton Rd, Westford, MA 01886, USA
|
||||||
|
|
||||||
N: Martin Josfsson
|
N: Martin Josfsson
|
||||||
E: gandalf@wlug.westbo.se
|
E: gandalf@wlug.westbo.se
|
||||||
|
|
|
@ -21,6 +21,9 @@ Changes
|
||||||
- list of changes that break older software packages.
|
- list of changes that break older software packages.
|
||||||
CodingStyle
|
CodingStyle
|
||||||
- how the boss likes the C code in the kernel to look.
|
- how the boss likes the C code in the kernel to look.
|
||||||
|
development-process/
|
||||||
|
- An extended tutorial on how to work with the kernel development
|
||||||
|
process.
|
||||||
DMA-API.txt
|
DMA-API.txt
|
||||||
- DMA API, pci_ API & extensions for non-consistent memory machines.
|
- DMA API, pci_ API & extensions for non-consistent memory machines.
|
||||||
DMA-ISA-LPC.txt
|
DMA-ISA-LPC.txt
|
||||||
|
@ -159,8 +162,6 @@ hayes-esp.txt
|
||||||
- info on using the Hayes ESP serial driver.
|
- info on using the Hayes ESP serial driver.
|
||||||
highuid.txt
|
highuid.txt
|
||||||
- notes on the change from 16 bit to 32 bit user/group IDs.
|
- notes on the change from 16 bit to 32 bit user/group IDs.
|
||||||
hpet.txt
|
|
||||||
- High Precision Event Timer Driver for Linux.
|
|
||||||
timers/
|
timers/
|
||||||
- info on the timer related topics
|
- info on the timer related topics
|
||||||
hw_random.txt
|
hw_random.txt
|
||||||
|
@ -251,8 +252,6 @@ mono.txt
|
||||||
- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
|
- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
|
||||||
moxa-smartio
|
moxa-smartio
|
||||||
- file with info on installing/using Moxa multiport serial driver.
|
- file with info on installing/using Moxa multiport serial driver.
|
||||||
mtrr.txt
|
|
||||||
- how to use PPro Memory Type Range Registers to increase performance.
|
|
||||||
mutex-design.txt
|
mutex-design.txt
|
||||||
- info on the generic mutex subsystem.
|
- info on the generic mutex subsystem.
|
||||||
namespaces/
|
namespaces/
|
||||||
|
|
|
@ -0,0 +1,62 @@
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/interface_capabilities
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/device_capabilities
|
||||||
|
Date: August 2008
|
||||||
|
Contact: Greg Kroah-Hartman <gregkh@suse.de>
|
||||||
|
Description:
|
||||||
|
These files show the various USB TMC capabilities as described
|
||||||
|
by the device itself. The full description of the bitfields
|
||||||
|
can be found in the USB TMC documents from the USB-IF entitled
|
||||||
|
"Universal Serial Bus Test and Measurement Class Specification
|
||||||
|
(USBTMC) Revision 1.0" section 4.2.1.8.
|
||||||
|
|
||||||
|
The files are read only.
|
||||||
|
|
||||||
|
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/usb488_interface_capabilities
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/usb488_device_capabilities
|
||||||
|
Date: August 2008
|
||||||
|
Contact: Greg Kroah-Hartman <gregkh@suse.de>
|
||||||
|
Description:
|
||||||
|
These files show the various USB TMC capabilities as described
|
||||||
|
by the device itself. The full description of the bitfields
|
||||||
|
can be found in the USB TMC documents from the USB-IF entitled
|
||||||
|
"Universal Serial Bus Test and Measurement Class, Subclass
|
||||||
|
USB488 Specification (USBTMC-USB488) Revision 1.0" section
|
||||||
|
4.2.2.
|
||||||
|
|
||||||
|
The files are read only.
|
||||||
|
|
||||||
|
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/TermChar
|
||||||
|
Date: August 2008
|
||||||
|
Contact: Greg Kroah-Hartman <gregkh@suse.de>
|
||||||
|
Description:
|
||||||
|
This file is the TermChar value to be sent to the USB TMC
|
||||||
|
device as described by the document, "Universal Serial Bus Test
|
||||||
|
and Measurement Class Specification
|
||||||
|
(USBTMC) Revision 1.0" as published by the USB-IF.
|
||||||
|
|
||||||
|
Note that the TermCharEnabled file determines if this value is
|
||||||
|
sent to the device or not.
|
||||||
|
|
||||||
|
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/TermCharEnabled
|
||||||
|
Date: August 2008
|
||||||
|
Contact: Greg Kroah-Hartman <gregkh@suse.de>
|
||||||
|
Description:
|
||||||
|
This file determines if the TermChar is to be sent to the
|
||||||
|
device on every transaction or not. For more details about
|
||||||
|
this, please see the document, "Universal Serial Bus Test and
|
||||||
|
Measurement Class Specification (USBTMC) Revision 1.0" as
|
||||||
|
published by the USB-IF.
|
||||||
|
|
||||||
|
|
||||||
|
What: /sys/bus/usb/drivers/usbtmc/devices/*/auto_abort
|
||||||
|
Date: August 2008
|
||||||
|
Contact: Greg Kroah-Hartman <gregkh@suse.de>
|
||||||
|
Description:
|
||||||
|
This file determines if the the transaction of the USB TMC
|
||||||
|
device is to be automatically aborted if there is any error.
|
||||||
|
For more details about this, please see the document,
|
||||||
|
"Universal Serial Bus Test and Measurement Class Specification
|
||||||
|
(USBTMC) Revision 1.0" as published by the USB-IF.
|
|
@ -85,3 +85,19 @@ Description:
|
||||||
Users:
|
Users:
|
||||||
PowerTOP <power@bughost.org>
|
PowerTOP <power@bughost.org>
|
||||||
http://www.lesswatts.org/projects/powertop/
|
http://www.lesswatts.org/projects/powertop/
|
||||||
|
|
||||||
|
What: /sys/bus/usb/device/<busnum>-<devnum>...:<config num>-<interface num>/supports_autosuspend
|
||||||
|
Date: January 2008
|
||||||
|
KernelVersion: 2.6.27
|
||||||
|
Contact: Sarah Sharp <sarah.a.sharp@intel.com>
|
||||||
|
Description:
|
||||||
|
When read, this file returns 1 if the interface driver
|
||||||
|
for this interface supports autosuspend. It also
|
||||||
|
returns 1 if no driver has claimed this interface, as an
|
||||||
|
unclaimed interface will not stop the device from being
|
||||||
|
autosuspended if all other interface drivers are idle.
|
||||||
|
The file returns 0 if autosuspend support has not been
|
||||||
|
added to the driver.
|
||||||
|
Users:
|
||||||
|
USB PM tool
|
||||||
|
git://git.moblin.org/users/sarah/usb-pm-tool/
|
||||||
|
|
|
@ -0,0 +1,43 @@
|
||||||
|
Where: /sys/bus/usb/.../powered
|
||||||
|
Date: August 2008
|
||||||
|
Kernel Version: 2.6.26
|
||||||
|
Contact: Harrison Metzger <harrisonmetz@gmail.com>
|
||||||
|
Description: Controls whether the device's display will powered.
|
||||||
|
A value of 0 is off and a non-zero value is on.
|
||||||
|
|
||||||
|
Where: /sys/bus/usb/.../mode_msb
|
||||||
|
Where: /sys/bus/usb/.../mode_lsb
|
||||||
|
Date: August 2008
|
||||||
|
Kernel Version: 2.6.26
|
||||||
|
Contact: Harrison Metzger <harrisonmetz@gmail.com>
|
||||||
|
Description: Controls the devices display mode.
|
||||||
|
For a 6 character display the values are
|
||||||
|
MSB 0x06; LSB 0x3F, and
|
||||||
|
for an 8 character display the values are
|
||||||
|
MSB 0x08; LSB 0xFF.
|
||||||
|
|
||||||
|
Where: /sys/bus/usb/.../textmode
|
||||||
|
Date: August 2008
|
||||||
|
Kernel Version: 2.6.26
|
||||||
|
Contact: Harrison Metzger <harrisonmetz@gmail.com>
|
||||||
|
Description: Controls the way the device interprets its text buffer.
|
||||||
|
raw: each character controls its segment manually
|
||||||
|
hex: each character is between 0-15
|
||||||
|
ascii: each character is between '0'-'9' and 'A'-'F'.
|
||||||
|
|
||||||
|
Where: /sys/bus/usb/.../text
|
||||||
|
Date: August 2008
|
||||||
|
Kernel Version: 2.6.26
|
||||||
|
Contact: Harrison Metzger <harrisonmetz@gmail.com>
|
||||||
|
Description: The text (or data) for the device to display
|
||||||
|
|
||||||
|
Where: /sys/bus/usb/.../decimals
|
||||||
|
Date: August 2008
|
||||||
|
Kernel Version: 2.6.26
|
||||||
|
Contact: Harrison Metzger <harrisonmetz@gmail.com>
|
||||||
|
Description: Controls the decimal places on the device.
|
||||||
|
To set the nth decimal place, give this field
|
||||||
|
the value of 10 ** n. Assume this field has
|
||||||
|
the value k and has 1 or more decimal places set,
|
||||||
|
to set the mth place (where m is not already set),
|
||||||
|
change this fields value to k + 10 ** m.
|
|
@ -1,7 +1,7 @@
|
||||||
What: /sys/class/regulator/.../state
|
What: /sys/class/regulator/.../state
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
state. This holds the regulator output state.
|
state. This holds the regulator output state.
|
||||||
|
@ -27,7 +27,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../type
|
What: /sys/class/regulator/.../type
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
type. This holds the regulator type.
|
type. This holds the regulator type.
|
||||||
|
@ -51,7 +51,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../microvolts
|
What: /sys/class/regulator/.../microvolts
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
microvolts. This holds the regulator output voltage setting
|
microvolts. This holds the regulator output voltage setting
|
||||||
|
@ -65,7 +65,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../microamps
|
What: /sys/class/regulator/.../microamps
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
microamps. This holds the regulator output current limit
|
microamps. This holds the regulator output current limit
|
||||||
|
@ -79,7 +79,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../opmode
|
What: /sys/class/regulator/.../opmode
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
opmode. This holds the regulator operating mode setting.
|
opmode. This holds the regulator operating mode setting.
|
||||||
|
@ -102,7 +102,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../min_microvolts
|
What: /sys/class/regulator/.../min_microvolts
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
min_microvolts. This holds the minimum safe working regulator
|
min_microvolts. This holds the minimum safe working regulator
|
||||||
|
@ -116,7 +116,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../max_microvolts
|
What: /sys/class/regulator/.../max_microvolts
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
max_microvolts. This holds the maximum safe working regulator
|
max_microvolts. This holds the maximum safe working regulator
|
||||||
|
@ -130,7 +130,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../min_microamps
|
What: /sys/class/regulator/.../min_microamps
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
min_microamps. This holds the minimum safe working regulator
|
min_microamps. This holds the minimum safe working regulator
|
||||||
|
@ -145,7 +145,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../max_microamps
|
What: /sys/class/regulator/.../max_microamps
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
max_microamps. This holds the maximum safe working regulator
|
max_microamps. This holds the maximum safe working regulator
|
||||||
|
@ -157,10 +157,23 @@ Description:
|
||||||
platform code.
|
platform code.
|
||||||
|
|
||||||
|
|
||||||
|
What: /sys/class/regulator/.../name
|
||||||
|
Date: October 2008
|
||||||
|
KernelVersion: 2.6.28
|
||||||
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
|
Description:
|
||||||
|
Each regulator directory will contain a field called
|
||||||
|
name. This holds a string identifying the regulator for
|
||||||
|
display purposes.
|
||||||
|
|
||||||
|
NOTE: this will be empty if no suitable name is provided
|
||||||
|
by platform or regulator drivers.
|
||||||
|
|
||||||
|
|
||||||
What: /sys/class/regulator/.../num_users
|
What: /sys/class/regulator/.../num_users
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
num_users. This holds the number of consumer devices that
|
num_users. This holds the number of consumer devices that
|
||||||
|
@ -170,7 +183,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../requested_microamps
|
What: /sys/class/regulator/.../requested_microamps
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
requested_microamps. This holds the total requested load
|
requested_microamps. This holds the total requested load
|
||||||
|
@ -181,7 +194,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../parent
|
What: /sys/class/regulator/.../parent
|
||||||
Date: April 2008
|
Date: April 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Some regulator directories will contain a link called parent.
|
Some regulator directories will contain a link called parent.
|
||||||
This points to the parent or supply regulator if one exists.
|
This points to the parent or supply regulator if one exists.
|
||||||
|
@ -189,7 +202,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_mem_microvolts
|
What: /sys/class/regulator/.../suspend_mem_microvolts
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_mem_microvolts. This holds the regulator output
|
suspend_mem_microvolts. This holds the regulator output
|
||||||
|
@ -203,7 +216,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_disk_microvolts
|
What: /sys/class/regulator/.../suspend_disk_microvolts
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_disk_microvolts. This holds the regulator output
|
suspend_disk_microvolts. This holds the regulator output
|
||||||
|
@ -217,7 +230,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_standby_microvolts
|
What: /sys/class/regulator/.../suspend_standby_microvolts
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_standby_microvolts. This holds the regulator output
|
suspend_standby_microvolts. This holds the regulator output
|
||||||
|
@ -231,7 +244,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_mem_mode
|
What: /sys/class/regulator/.../suspend_mem_mode
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_mem_mode. This holds the regulator operating mode
|
suspend_mem_mode. This holds the regulator operating mode
|
||||||
|
@ -245,7 +258,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_disk_mode
|
What: /sys/class/regulator/.../suspend_disk_mode
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_disk_mode. This holds the regulator operating mode
|
suspend_disk_mode. This holds the regulator operating mode
|
||||||
|
@ -258,7 +271,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_standby_mode
|
What: /sys/class/regulator/.../suspend_standby_mode
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_standby_mode. This holds the regulator operating mode
|
suspend_standby_mode. This holds the regulator operating mode
|
||||||
|
@ -272,7 +285,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_mem_state
|
What: /sys/class/regulator/.../suspend_mem_state
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_mem_state. This holds the regulator operating state
|
suspend_mem_state. This holds the regulator operating state
|
||||||
|
@ -287,7 +300,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_disk_state
|
What: /sys/class/regulator/.../suspend_disk_state
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_disk_state. This holds the regulator operating state
|
suspend_disk_state. This holds the regulator operating state
|
||||||
|
@ -302,7 +315,7 @@ Description:
|
||||||
What: /sys/class/regulator/.../suspend_standby_state
|
What: /sys/class/regulator/.../suspend_standby_state
|
||||||
Date: May 2008
|
Date: May 2008
|
||||||
KernelVersion: 2.6.26
|
KernelVersion: 2.6.26
|
||||||
Contact: Liam Girdwood <lg@opensource.wolfsonmicro.com>
|
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
|
||||||
Description:
|
Description:
|
||||||
Each regulator directory will contain a field called
|
Each regulator directory will contain a field called
|
||||||
suspend_standby_state. This holds the regulator operating
|
suspend_standby_state. This holds the regulator operating
|
||||||
|
|
|
@ -0,0 +1,13 @@
|
||||||
|
What: /sys/kernel/profile
|
||||||
|
Date: September 2008
|
||||||
|
Contact: Dave Hansen <dave@linux.vnet.ibm.com>
|
||||||
|
Description:
|
||||||
|
/sys/kernel/profile is the runtime equivalent
|
||||||
|
of the boot-time profile= option.
|
||||||
|
|
||||||
|
You can get the same effect running:
|
||||||
|
|
||||||
|
echo 2 > /sys/kernel/profile
|
||||||
|
|
||||||
|
as you would by issuing profile=2 on the boot
|
||||||
|
command line.
|
|
@ -337,7 +337,7 @@ With scatterlists, you use the resulting mapping like this:
|
||||||
int i, count = dma_map_sg(dev, sglist, nents, direction);
|
int i, count = dma_map_sg(dev, sglist, nents, direction);
|
||||||
struct scatterlist *sg;
|
struct scatterlist *sg;
|
||||||
|
|
||||||
for (i = 0, sg = sglist; i < count; i++, sg++) {
|
for_each_sg(sglist, sg, count, i) {
|
||||||
hw_address[i] = sg_dma_address(sg);
|
hw_address[i] = sg_dma_address(sg);
|
||||||
hw_len[i] = sg_dma_len(sg);
|
hw_len[i] = sg_dma_len(sg);
|
||||||
}
|
}
|
||||||
|
|
|
@ -6,7 +6,7 @@
|
||||||
# To add a new book the only step required is to add the book to the
|
# To add a new book the only step required is to add the book to the
|
||||||
# list of DOCBOOKS.
|
# list of DOCBOOKS.
|
||||||
|
|
||||||
DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
|
DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml \
|
||||||
kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
|
kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
|
||||||
procfs-guide.xml writing_usb_driver.xml networking.xml \
|
procfs-guide.xml writing_usb_driver.xml networking.xml \
|
||||||
kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
|
kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
|
||||||
|
|
|
@ -557,6 +557,9 @@ Near-term plans include converting all of them, except for "gadgetfs".
|
||||||
</para>
|
</para>
|
||||||
|
|
||||||
!Edrivers/usb/gadget/f_acm.c
|
!Edrivers/usb/gadget/f_acm.c
|
||||||
|
!Edrivers/usb/gadget/f_ecm.c
|
||||||
|
!Edrivers/usb/gadget/f_subset.c
|
||||||
|
!Edrivers/usb/gadget/f_obex.c
|
||||||
!Edrivers/usb/gadget/f_serial.c
|
!Edrivers/usb/gadget/f_serial.c
|
||||||
|
|
||||||
</sect1>
|
</sect1>
|
||||||
|
|
|
@ -283,6 +283,7 @@ X!Earch/x86/kernel/mca_32.c
|
||||||
<chapter id="security">
|
<chapter id="security">
|
||||||
<title>Security Framework</title>
|
<title>Security Framework</title>
|
||||||
!Isecurity/security.c
|
!Isecurity/security.c
|
||||||
|
!Esecurity/inode.c
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
<chapter id="audit">
|
<chapter id="audit">
|
||||||
|
@ -364,6 +365,10 @@ X!Edrivers/pnp/system.c
|
||||||
!Eblock/blk-barrier.c
|
!Eblock/blk-barrier.c
|
||||||
!Eblock/blk-tag.c
|
!Eblock/blk-tag.c
|
||||||
!Iblock/blk-tag.c
|
!Iblock/blk-tag.c
|
||||||
|
!Eblock/blk-integrity.c
|
||||||
|
!Iblock/blktrace.c
|
||||||
|
!Iblock/genhd.c
|
||||||
|
!Eblock/genhd.c
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
<chapter id="chrdev">
|
<chapter id="chrdev">
|
||||||
|
|
|
@ -1105,7 +1105,7 @@ static struct block_device_operations opt_fops = {
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>
|
<para>
|
||||||
Function names as strings (__FUNCTION__).
|
Function names as strings (__func__).
|
||||||
</para>
|
</para>
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
|
|
|
@ -145,7 +145,6 @@ usage should require reading the full document.
|
||||||
this though and the recommendation to allow only a single
|
this though and the recommendation to allow only a single
|
||||||
interface in STA mode at first!
|
interface in STA mode at first!
|
||||||
</para>
|
</para>
|
||||||
!Finclude/net/mac80211.h ieee80211_if_types
|
|
||||||
!Finclude/net/mac80211.h ieee80211_if_init_conf
|
!Finclude/net/mac80211.h ieee80211_if_init_conf
|
||||||
!Finclude/net/mac80211.h ieee80211_if_conf
|
!Finclude/net/mac80211.h ieee80211_if_conf
|
||||||
</chapter>
|
</chapter>
|
||||||
|
@ -177,8 +176,7 @@ usage should require reading the full document.
|
||||||
<title>functions/definitions</title>
|
<title>functions/definitions</title>
|
||||||
!Finclude/net/mac80211.h ieee80211_rx_status
|
!Finclude/net/mac80211.h ieee80211_rx_status
|
||||||
!Finclude/net/mac80211.h mac80211_rx_flags
|
!Finclude/net/mac80211.h mac80211_rx_flags
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_control
|
!Finclude/net/mac80211.h ieee80211_tx_info
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_status_flags
|
|
||||||
!Finclude/net/mac80211.h ieee80211_rx
|
!Finclude/net/mac80211.h ieee80211_rx
|
||||||
!Finclude/net/mac80211.h ieee80211_rx_irqsafe
|
!Finclude/net/mac80211.h ieee80211_rx_irqsafe
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_status
|
!Finclude/net/mac80211.h ieee80211_tx_status
|
||||||
|
@ -189,12 +187,11 @@ usage should require reading the full document.
|
||||||
!Finclude/net/mac80211.h ieee80211_ctstoself_duration
|
!Finclude/net/mac80211.h ieee80211_ctstoself_duration
|
||||||
!Finclude/net/mac80211.h ieee80211_generic_frame_duration
|
!Finclude/net/mac80211.h ieee80211_generic_frame_duration
|
||||||
!Finclude/net/mac80211.h ieee80211_get_hdrlen_from_skb
|
!Finclude/net/mac80211.h ieee80211_get_hdrlen_from_skb
|
||||||
!Finclude/net/mac80211.h ieee80211_get_hdrlen
|
!Finclude/net/mac80211.h ieee80211_hdrlen
|
||||||
!Finclude/net/mac80211.h ieee80211_wake_queue
|
!Finclude/net/mac80211.h ieee80211_wake_queue
|
||||||
!Finclude/net/mac80211.h ieee80211_stop_queue
|
!Finclude/net/mac80211.h ieee80211_stop_queue
|
||||||
!Finclude/net/mac80211.h ieee80211_start_queues
|
|
||||||
!Finclude/net/mac80211.h ieee80211_stop_queues
|
|
||||||
!Finclude/net/mac80211.h ieee80211_wake_queues
|
!Finclude/net/mac80211.h ieee80211_wake_queues
|
||||||
|
!Finclude/net/mac80211.h ieee80211_stop_queues
|
||||||
</sect1>
|
</sect1>
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
|
@ -230,8 +227,7 @@ usage should require reading the full document.
|
||||||
<title>Multiple queues and QoS support</title>
|
<title>Multiple queues and QoS support</title>
|
||||||
<para>TBD</para>
|
<para>TBD</para>
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_queue_params
|
!Finclude/net/mac80211.h ieee80211_tx_queue_params
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_queue_stats_data
|
!Finclude/net/mac80211.h ieee80211_tx_queue_stats
|
||||||
!Finclude/net/mac80211.h ieee80211_tx_queue
|
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
<chapter id="AP">
|
<chapter id="AP">
|
||||||
|
|
|
@ -14,17 +14,20 @@
|
||||||
<othername>(J.A.K.)</othername>
|
<othername>(J.A.K.)</othername>
|
||||||
<surname>Mouw</surname>
|
<surname>Mouw</surname>
|
||||||
<affiliation>
|
<affiliation>
|
||||||
<orgname>Delft University of Technology</orgname>
|
|
||||||
<orgdiv>Faculty of Information Technology and Systems</orgdiv>
|
|
||||||
<address>
|
<address>
|
||||||
<email>J.A.K.Mouw@its.tudelft.nl</email>
|
<email>mouw@nl.linux.org</email>
|
||||||
<pob>PO BOX 5031</pob>
|
|
||||||
<postcode>2600 GA</postcode>
|
|
||||||
<city>Delft</city>
|
|
||||||
<country>The Netherlands</country>
|
|
||||||
</address>
|
</address>
|
||||||
</affiliation>
|
</affiliation>
|
||||||
</author>
|
</author>
|
||||||
|
<othercredit>
|
||||||
|
<contrib>
|
||||||
|
This software and documentation were written while working on the
|
||||||
|
LART computing board
|
||||||
|
(<ulink url="http://www.lartmaker.nl/">http://www.lartmaker.nl/</ulink>),
|
||||||
|
which was sponsored by the Delt University of Technology projects
|
||||||
|
Mobile Multi-media Communications and Ubiquitous Communications.
|
||||||
|
</contrib>
|
||||||
|
</othercredit>
|
||||||
</authorgroup>
|
</authorgroup>
|
||||||
|
|
||||||
<revhistory>
|
<revhistory>
|
||||||
|
@ -108,18 +111,6 @@
|
||||||
proofreading.
|
proofreading.
|
||||||
</para>
|
</para>
|
||||||
|
|
||||||
<para>
|
|
||||||
This documentation was written while working on the LART
|
|
||||||
computing board (<ulink
|
|
||||||
url="http://www.lart.tudelft.nl/">http://www.lart.tudelft.nl/</ulink>),
|
|
||||||
which is sponsored by the Mobile Multi-media Communications
|
|
||||||
(<ulink
|
|
||||||
url="http://www.mmc.tudelft.nl/">http://www.mmc.tudelft.nl/</ulink>)
|
|
||||||
and Ubiquitous Communications (<ulink
|
|
||||||
url="http://www.ubicom.tudelft.nl/">http://www.ubicom.tudelft.nl/</ulink>)
|
|
||||||
projects.
|
|
||||||
</para>
|
|
||||||
|
|
||||||
<para>
|
<para>
|
||||||
Erik
|
Erik
|
||||||
</para>
|
</para>
|
||||||
|
|
|
@ -1,28 +1,16 @@
|
||||||
/*
|
/*
|
||||||
* procfs_example.c: an example proc interface
|
* procfs_example.c: an example proc interface
|
||||||
*
|
*
|
||||||
* Copyright (C) 2001, Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
|
* Copyright (C) 2001, Erik Mouw (mouw@nl.linux.org)
|
||||||
*
|
*
|
||||||
* This file accompanies the procfs-guide in the Linux kernel
|
* This file accompanies the procfs-guide in the Linux kernel
|
||||||
* source. Its main use is to demonstrate the concepts and
|
* source. Its main use is to demonstrate the concepts and
|
||||||
* functions described in the guide.
|
* functions described in the guide.
|
||||||
*
|
*
|
||||||
* This software has been developed while working on the LART
|
* This software has been developed while working on the LART
|
||||||
* computing board (http://www.lart.tudelft.nl/), which is
|
* computing board (http://www.lartmaker.nl), which was sponsored
|
||||||
* sponsored by the Mobile Multi-media Communications
|
* by the Delt University of Technology projects Mobile Multi-media
|
||||||
* (http://www.mmc.tudelft.nl/) and Ubiquitous Communications
|
* Communications and Ubiquitous Communications.
|
||||||
* (http://www.ubicom.tudelft.nl/) projects.
|
|
||||||
*
|
|
||||||
* The author can be reached at:
|
|
||||||
*
|
|
||||||
* Erik Mouw
|
|
||||||
* Information and Communication Theory Group
|
|
||||||
* Faculty of Information Technology and Systems
|
|
||||||
* Delft University of Technology
|
|
||||||
* P.O. Box 5031
|
|
||||||
* 2600 GA Delft
|
|
||||||
* The Netherlands
|
|
||||||
*
|
|
||||||
*
|
*
|
||||||
* This program is free software; you can redistribute
|
* This program is free software; you can redistribute
|
||||||
* it and/or modify it under the terms of the GNU General
|
* it and/or modify it under the terms of the GNU General
|
||||||
|
|
Разница между файлами не показана из-за своего большого размера
Загрузить разницу
|
@ -112,7 +112,7 @@ required reading:
|
||||||
|
|
||||||
Other excellent descriptions of how to create patches properly are:
|
Other excellent descriptions of how to create patches properly are:
|
||||||
"The Perfect Patch"
|
"The Perfect Patch"
|
||||||
http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
|
http://userweb.kernel.org/~akpm/stuff/tpp.txt
|
||||||
"Linux kernel patch submission format"
|
"Linux kernel patch submission format"
|
||||||
http://linux.yyz.us/patch-format.html
|
http://linux.yyz.us/patch-format.html
|
||||||
|
|
||||||
|
@ -620,7 +620,7 @@ all time. It should describe the patch completely, containing:
|
||||||
For more details on what this should all look like, please see the
|
For more details on what this should all look like, please see the
|
||||||
ChangeLog section of the document:
|
ChangeLog section of the document:
|
||||||
"The Perfect Patch"
|
"The Perfect Patch"
|
||||||
http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
|
http://userweb.kernel.org/~akpm/stuff/tpp.txt
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
|
@ -236,10 +236,8 @@ software system can set different pages for controlling accesses to the
|
||||||
MSI-X structure. The implementation of MSI support requires the PCI
|
MSI-X structure. The implementation of MSI support requires the PCI
|
||||||
subsystem, not a device driver, to maintain full control of the MSI-X
|
subsystem, not a device driver, to maintain full control of the MSI-X
|
||||||
table/MSI-X PBA (Pending Bit Array) and MMIO address space of the MSI-X
|
table/MSI-X PBA (Pending Bit Array) and MMIO address space of the MSI-X
|
||||||
table/MSI-X PBA. A device driver is prohibited from requesting the MMIO
|
table/MSI-X PBA. A device driver should not access the MMIO address
|
||||||
address space of the MSI-X table/MSI-X PBA. Otherwise, the PCI subsystem
|
space of the MSI-X table/MSI-X PBA.
|
||||||
will fail enabling MSI-X on its hardware device when it calls the function
|
|
||||||
pci_enable_msix().
|
|
||||||
|
|
||||||
5.3.2 API pci_enable_msix
|
5.3.2 API pci_enable_msix
|
||||||
|
|
||||||
|
|
|
@ -163,6 +163,10 @@ need pass only as many optional fields as necessary:
|
||||||
o class and classmask fields default to 0
|
o class and classmask fields default to 0
|
||||||
o driver_data defaults to 0UL.
|
o driver_data defaults to 0UL.
|
||||||
|
|
||||||
|
Note that driver_data must match the value used by any of the pci_device_id
|
||||||
|
entries defined in the driver. This makes the driver_data field mandatory
|
||||||
|
if all the pci_device_id entries have a non-zero driver_data value.
|
||||||
|
|
||||||
Once added, the driver probe routine will be invoked for any unclaimed
|
Once added, the driver probe routine will be invoked for any unclaimed
|
||||||
PCI devices listed in its (newly updated) pci_ids list.
|
PCI devices listed in its (newly updated) pci_ids list.
|
||||||
|
|
||||||
|
|
|
@ -203,22 +203,17 @@ to mmio_enabled.
|
||||||
|
|
||||||
3.3 helper functions
|
3.3 helper functions
|
||||||
|
|
||||||
3.3.1 int pci_find_aer_capability(struct pci_dev *dev);
|
3.3.1 int pci_enable_pcie_error_reporting(struct pci_dev *dev);
|
||||||
pci_find_aer_capability locates the PCI Express AER capability
|
|
||||||
in the device configuration space. If the device doesn't support
|
|
||||||
PCI-Express AER, the function returns 0.
|
|
||||||
|
|
||||||
3.3.2 int pci_enable_pcie_error_reporting(struct pci_dev *dev);
|
|
||||||
pci_enable_pcie_error_reporting enables the device to send error
|
pci_enable_pcie_error_reporting enables the device to send error
|
||||||
messages to root port when an error is detected. Note that devices
|
messages to root port when an error is detected. Note that devices
|
||||||
don't enable the error reporting by default, so device drivers need
|
don't enable the error reporting by default, so device drivers need
|
||||||
call this function to enable it.
|
call this function to enable it.
|
||||||
|
|
||||||
3.3.3 int pci_disable_pcie_error_reporting(struct pci_dev *dev);
|
3.3.2 int pci_disable_pcie_error_reporting(struct pci_dev *dev);
|
||||||
pci_disable_pcie_error_reporting disables the device to send error
|
pci_disable_pcie_error_reporting disables the device to send error
|
||||||
messages to root port when an error is detected.
|
messages to root port when an error is detected.
|
||||||
|
|
||||||
3.3.4 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
|
3.3.3 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
|
||||||
pci_cleanup_aer_uncorrect_error_status cleanups the uncorrectable
|
pci_cleanup_aer_uncorrect_error_status cleanups the uncorrectable
|
||||||
error status register.
|
error status register.
|
||||||
|
|
||||||
|
|
|
@ -210,7 +210,7 @@ over a rather long period of time, but improvements are always welcome!
|
||||||
number of updates per grace period.
|
number of updates per grace period.
|
||||||
|
|
||||||
9. All RCU list-traversal primitives, which include
|
9. All RCU list-traversal primitives, which include
|
||||||
rcu_dereference(), list_for_each_rcu(), list_for_each_entry_rcu(),
|
rcu_dereference(), list_for_each_entry_rcu(),
|
||||||
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
|
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
|
||||||
must be either within an RCU read-side critical section or
|
must be either within an RCU read-side critical section or
|
||||||
must be protected by appropriate update-side locks. RCU
|
must be protected by appropriate update-side locks. RCU
|
||||||
|
|
|
@ -29,9 +29,9 @@ release_referenced() delete()
|
||||||
}
|
}
|
||||||
|
|
||||||
If this list/array is made lock free using RCU as in changing the
|
If this list/array is made lock free using RCU as in changing the
|
||||||
write_lock() in add() and delete() to spin_lock and changing read_lock
|
write_lock() in add() and delete() to spin_lock() and changing read_lock()
|
||||||
in search_and_reference to rcu_read_lock(), the atomic_get in
|
in search_and_reference() to rcu_read_lock(), the atomic_inc() in
|
||||||
search_and_reference could potentially hold reference to an element which
|
search_and_reference() could potentially hold reference to an element which
|
||||||
has already been deleted from the list/array. Use atomic_inc_not_zero()
|
has already been deleted from the list/array. Use atomic_inc_not_zero()
|
||||||
in this scenario as follows:
|
in this scenario as follows:
|
||||||
|
|
||||||
|
@ -40,20 +40,20 @@ add() search_and_reference()
|
||||||
{ {
|
{ {
|
||||||
alloc_object rcu_read_lock();
|
alloc_object rcu_read_lock();
|
||||||
... search_for_element
|
... search_for_element
|
||||||
atomic_set(&el->rc, 1); if (atomic_inc_not_zero(&el->rc)) {
|
atomic_set(&el->rc, 1); if (!atomic_inc_not_zero(&el->rc)) {
|
||||||
write_lock(&list_lock); rcu_read_unlock();
|
spin_lock(&list_lock); rcu_read_unlock();
|
||||||
return FAIL;
|
return FAIL;
|
||||||
add_element }
|
add_element }
|
||||||
... ...
|
... ...
|
||||||
write_unlock(&list_lock); rcu_read_unlock();
|
spin_unlock(&list_lock); rcu_read_unlock();
|
||||||
} }
|
} }
|
||||||
3. 4.
|
3. 4.
|
||||||
release_referenced() delete()
|
release_referenced() delete()
|
||||||
{ {
|
{ {
|
||||||
... write_lock(&list_lock);
|
... spin_lock(&list_lock);
|
||||||
if (atomic_dec_and_test(&el->rc)) ...
|
if (atomic_dec_and_test(&el->rc)) ...
|
||||||
call_rcu(&el->head, el_free); delete_element
|
call_rcu(&el->head, el_free); delete_element
|
||||||
... write_unlock(&list_lock);
|
... spin_unlock(&list_lock);
|
||||||
} ...
|
} ...
|
||||||
if (atomic_dec_and_test(&el->rc))
|
if (atomic_dec_and_test(&el->rc))
|
||||||
call_rcu(&el->head, el_free);
|
call_rcu(&el->head, el_free);
|
||||||
|
|
|
@ -786,8 +786,6 @@ RCU pointer/list traversal:
|
||||||
list_for_each_entry_rcu
|
list_for_each_entry_rcu
|
||||||
hlist_for_each_entry_rcu
|
hlist_for_each_entry_rcu
|
||||||
|
|
||||||
list_for_each_rcu (to be deprecated in favor of
|
|
||||||
list_for_each_entry_rcu)
|
|
||||||
list_for_each_continue_rcu (to be deprecated in favor of new
|
list_for_each_continue_rcu (to be deprecated in favor of new
|
||||||
list_for_each_entry_continue_rcu)
|
list_for_each_entry_continue_rcu)
|
||||||
|
|
||||||
|
|
|
@ -1,5 +1,5 @@
|
||||||
Linux 2.4.2 Secure Attention Key (SAK) handling
|
Linux 2.4.2 Secure Attention Key (SAK) handling
|
||||||
18 March 2001, Andrew Morton <akpm@osdl.org>
|
18 March 2001, Andrew Morton
|
||||||
|
|
||||||
An operating system's Secure Attention Key is a security tool which is
|
An operating system's Secure Attention Key is a security tool which is
|
||||||
provided as protection against trojan password capturing programs. It
|
provided as protection against trojan password capturing programs. It
|
||||||
|
|
|
@ -0,0 +1,27 @@
|
||||||
|
If you want to use SELinux, chances are you will want
|
||||||
|
to use the distro-provided policies, or install the
|
||||||
|
latest reference policy release from
|
||||||
|
http://oss.tresys.com/projects/refpolicy
|
||||||
|
|
||||||
|
However, if you want to install a dummy policy for
|
||||||
|
testing, you can do using 'mdp' provided under
|
||||||
|
scripts/selinux. Note that this requires the selinux
|
||||||
|
userspace to be installed - in particular you will
|
||||||
|
need checkpolicy to compile a kernel, and setfiles and
|
||||||
|
fixfiles to label the filesystem.
|
||||||
|
|
||||||
|
1. Compile the kernel with selinux enabled.
|
||||||
|
2. Type 'make' to compile mdp.
|
||||||
|
3. Make sure that you are not running with
|
||||||
|
SELinux enabled and a real policy. If
|
||||||
|
you are, reboot with selinux disabled
|
||||||
|
before continuing.
|
||||||
|
4. Run install_policy.sh:
|
||||||
|
cd scripts/selinux
|
||||||
|
sh install_policy.sh
|
||||||
|
|
||||||
|
Step 4 will create a new dummy policy valid for your
|
||||||
|
kernel, with a single selinux user, role, and type.
|
||||||
|
It will compile the policy, will set your SELINUXTYPE to
|
||||||
|
dummy in /etc/selinux/config, install the compiled policy
|
||||||
|
as 'dummy', and relabel your filesystem.
|
|
@ -85,3 +85,6 @@ kernel patches.
|
||||||
23: Tested after it has been merged into the -mm patchset to make sure
|
23: Tested after it has been merged into the -mm patchset to make sure
|
||||||
that it still works with all of the other queued patches and various
|
that it still works with all of the other queued patches and various
|
||||||
changes in the VM, VFS, and other subsystems.
|
changes in the VM, VFS, and other subsystems.
|
||||||
|
|
||||||
|
24: All memory barriers {e.g., barrier(), rmb(), wmb()} need a comment in the
|
||||||
|
source code that explains the logic of what they are doing and why.
|
||||||
|
|
|
@ -41,7 +41,7 @@ Linux 2.4:
|
||||||
Linux 2.6:
|
Linux 2.6:
|
||||||
The same rules apply as 2.4 except that you should follow linux-kernel
|
The same rules apply as 2.4 except that you should follow linux-kernel
|
||||||
to track changes in API's. The final contact point for Linux 2.6
|
to track changes in API's. The final contact point for Linux 2.6
|
||||||
submissions is Andrew Morton <akpm@osdl.org>.
|
submissions is Andrew Morton.
|
||||||
|
|
||||||
What Criteria Determine Acceptance
|
What Criteria Determine Acceptance
|
||||||
----------------------------------
|
----------------------------------
|
||||||
|
|
|
@ -77,7 +77,7 @@ Quilt:
|
||||||
http://savannah.nongnu.org/projects/quilt
|
http://savannah.nongnu.org/projects/quilt
|
||||||
|
|
||||||
Andrew Morton's patch scripts:
|
Andrew Morton's patch scripts:
|
||||||
http://www.zip.com.au/~akpm/linux/patches/
|
http://userweb.kernel.org/~akpm/stuff/patch-scripts.tar.gz
|
||||||
Instead of these scripts, quilt is the recommended patch management
|
Instead of these scripts, quilt is the recommended patch management
|
||||||
tool (see above).
|
tool (see above).
|
||||||
|
|
||||||
|
@ -405,7 +405,7 @@ person it names. This tag documents that potentially interested parties
|
||||||
have been included in the discussion
|
have been included in the discussion
|
||||||
|
|
||||||
|
|
||||||
14) Using Test-by: and Reviewed-by:
|
14) Using Tested-by: and Reviewed-by:
|
||||||
|
|
||||||
A Tested-by: tag indicates that the patch has been successfully tested (in
|
A Tested-by: tag indicates that the patch has been successfully tested (in
|
||||||
some environment) by the person named. This tag informs maintainers that
|
some environment) by the person named. This tag informs maintainers that
|
||||||
|
@ -653,7 +653,7 @@ SECTION 3 - REFERENCES
|
||||||
----------------------
|
----------------------
|
||||||
|
|
||||||
Andrew Morton, "The perfect patch" (tpp).
|
Andrew Morton, "The perfect patch" (tpp).
|
||||||
<http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt>
|
<http://userweb.kernel.org/~akpm/stuff/tpp.txt>
|
||||||
|
|
||||||
Jeff Garzik, "Linux kernel patch submission format".
|
Jeff Garzik, "Linux kernel patch submission format".
|
||||||
<http://linux.yyz.us/patch-format.html>
|
<http://linux.yyz.us/patch-format.html>
|
||||||
|
@ -672,4 +672,9 @@ Kernel Documentation/CodingStyle:
|
||||||
|
|
||||||
Linus Torvalds's mail on the canonical patch format:
|
Linus Torvalds's mail on the canonical patch format:
|
||||||
<http://lkml.org/lkml/2005/4/7/183>
|
<http://lkml.org/lkml/2005/4/7/183>
|
||||||
|
|
||||||
|
Andi Kleen, "On submitting kernel patches"
|
||||||
|
Some strategies to get difficult or controversal changes in.
|
||||||
|
http://halobates.de/on-submitting-patches.pdf
|
||||||
|
|
||||||
--
|
--
|
||||||
|
|
|
@ -1,155 +0,0 @@
|
||||||
A Simple Guide to Configure KGDB
|
|
||||||
|
|
||||||
Sonic Zhang <sonic.zhang@analog.com>
|
|
||||||
Aug. 24th 2006
|
|
||||||
|
|
||||||
|
|
||||||
This KGDB patch enables the kernel developer to do source level debugging on
|
|
||||||
the kernel for the Blackfin architecture. The debugging works over either the
|
|
||||||
ethernet interface or one of the uarts. Both software breakpoints and
|
|
||||||
hardware breakpoints are supported in this version.
|
|
||||||
http://docs.blackfin.uclinux.org/doku.php?id=kgdb
|
|
||||||
|
|
||||||
|
|
||||||
2 known issues:
|
|
||||||
1. This bug:
|
|
||||||
http://blackfin.uclinux.org/tracker/index.php?func=detail&aid=544&group_id=18&atid=145
|
|
||||||
The GDB client for Blackfin uClinux causes incorrect values of local
|
|
||||||
variables to be displayed when the user breaks the running of kernel in GDB.
|
|
||||||
2. Because of a hardware bug in Blackfin 533 v1.0.3:
|
|
||||||
05000067 - Watchpoints (Hardware Breakpoints) are not supported
|
|
||||||
Hardware breakpoints cannot be set properly.
|
|
||||||
|
|
||||||
|
|
||||||
Debug over Ethernet:
|
|
||||||
|
|
||||||
1. Compile and install the cross platform version of gdb for blackfin, which
|
|
||||||
can be found at $(BINROOT)/bfin-elf-gdb.
|
|
||||||
|
|
||||||
2. Apply this patch to the 2.6.x kernel. Select the menuconfig option under
|
|
||||||
"Kernel hacking" -> "Kernel debugging" -> "KGDB: kernel debug with remote gdb".
|
|
||||||
With this selected, option "Full Symbolic/Source Debugging support" and
|
|
||||||
"Compile the kernel with frame pointers" are also selected.
|
|
||||||
|
|
||||||
3. Select option "KGDB: connect over (Ethernet)". Add "kgdboe=@target-IP/,@host-IP/" to
|
|
||||||
the option "Compiled-in Kernel Boot Parameter" under "Kernel hacking".
|
|
||||||
|
|
||||||
4. Connect minicom to the serial port and boot the kernel image.
|
|
||||||
|
|
||||||
5. Configure the IP "/> ifconfig eth0 target-IP"
|
|
||||||
|
|
||||||
6. Start GDB client "bfin-elf-gdb vmlinux".
|
|
||||||
|
|
||||||
7. Connect to the target "(gdb) target remote udp:target-IP:6443".
|
|
||||||
|
|
||||||
8. Set software breakpoint "(gdb) break sys_open".
|
|
||||||
|
|
||||||
9. Continue "(gdb) c".
|
|
||||||
|
|
||||||
10. Run ls in the target console "/> ls".
|
|
||||||
|
|
||||||
11. Breakpoint hits. "Breakpoint 1: sys_open(..."
|
|
||||||
|
|
||||||
12. Display local variables and function paramters.
|
|
||||||
(*) This operation gives wrong results, see known issue 1.
|
|
||||||
|
|
||||||
13. Single stepping "(gdb) si".
|
|
||||||
|
|
||||||
14. Remove breakpoint 1. "(gdb) del 1"
|
|
||||||
|
|
||||||
15. Set hardware breakpoint "(gdb) hbreak sys_open".
|
|
||||||
|
|
||||||
16. Continue "(gdb) c".
|
|
||||||
|
|
||||||
17. Run ls in the target console "/> ls".
|
|
||||||
|
|
||||||
18. Hardware breakpoint hits. "Breakpoint 1: sys_open(...".
|
|
||||||
(*) This hardware breakpoint will not be hit, see known issue 2.
|
|
||||||
|
|
||||||
19. Continue "(gdb) c".
|
|
||||||
|
|
||||||
20. Interrupt the target in GDB "Ctrl+C".
|
|
||||||
|
|
||||||
21. Detach from the target "(gdb) detach".
|
|
||||||
|
|
||||||
22. Exit GDB "(gdb) quit".
|
|
||||||
|
|
||||||
|
|
||||||
Debug over the UART:
|
|
||||||
|
|
||||||
1. Compile and install the cross platform version of gdb for blackfin, which
|
|
||||||
can be found at $(BINROOT)/bfin-elf-gdb.
|
|
||||||
|
|
||||||
2. Apply this patch to the 2.6.x kernel. Select the menuconfig option under
|
|
||||||
"Kernel hacking" -> "Kernel debugging" -> "KGDB: kernel debug with remote gdb".
|
|
||||||
With this selected, option "Full Symbolic/Source Debugging support" and
|
|
||||||
"Compile the kernel with frame pointers" are also selected.
|
|
||||||
|
|
||||||
3. Select option "KGDB: connect over (UART)". Set "KGDB: UART port number" to be
|
|
||||||
a different one from the console. Don't forget to change the mode of
|
|
||||||
blackfin serial driver to PIO. Otherwise kgdb works incorrectly on UART.
|
|
||||||
|
|
||||||
4. If you want connect to kgdb when the kernel boots, enable
|
|
||||||
"KGDB: Wait for gdb connection early"
|
|
||||||
|
|
||||||
5. Compile kernel.
|
|
||||||
|
|
||||||
6. Connect minicom to the serial port of the console and boot the kernel image.
|
|
||||||
|
|
||||||
7. Start GDB client "bfin-elf-gdb vmlinux".
|
|
||||||
|
|
||||||
8. Set the baud rate in GDB "(gdb) set remotebaud 57600".
|
|
||||||
|
|
||||||
9. Connect to the target on the second serial port "(gdb) target remote /dev/ttyS1".
|
|
||||||
|
|
||||||
10. Set software breakpoint "(gdb) break sys_open".
|
|
||||||
|
|
||||||
11. Continue "(gdb) c".
|
|
||||||
|
|
||||||
12. Run ls in the target console "/> ls".
|
|
||||||
|
|
||||||
13. A breakpoint is hit. "Breakpoint 1: sys_open(..."
|
|
||||||
|
|
||||||
14. All other operations are the same as that in KGDB over Ethernet.
|
|
||||||
|
|
||||||
|
|
||||||
Debug over the same UART as console:
|
|
||||||
|
|
||||||
1. Compile and install the cross platform version of gdb for blackfin, which
|
|
||||||
can be found at $(BINROOT)/bfin-elf-gdb.
|
|
||||||
|
|
||||||
2. Apply this patch to the 2.6.x kernel. Select the menuconfig option under
|
|
||||||
"Kernel hacking" -> "Kernel debugging" -> "KGDB: kernel debug with remote gdb".
|
|
||||||
With this selected, option "Full Symbolic/Source Debugging support" and
|
|
||||||
"Compile the kernel with frame pointers" are also selected.
|
|
||||||
|
|
||||||
3. Select option "KGDB: connect over UART". Set "KGDB: UART port number" to console.
|
|
||||||
Don't forget to change the mode of blackfin serial driver to PIO.
|
|
||||||
Otherwise kgdb works incorrectly on UART.
|
|
||||||
|
|
||||||
4. If you want connect to kgdb when the kernel boots, enable
|
|
||||||
"KGDB: Wait for gdb connection early"
|
|
||||||
|
|
||||||
5. Connect minicom to the serial port and boot the kernel image.
|
|
||||||
|
|
||||||
6. (Optional) Ask target to wait for gdb connection by entering Ctrl+A. In minicom, you should enter Ctrl+A+A.
|
|
||||||
|
|
||||||
7. Start GDB client "bfin-elf-gdb vmlinux".
|
|
||||||
|
|
||||||
8. Set the baud rate in GDB "(gdb) set remotebaud 57600".
|
|
||||||
|
|
||||||
9. Connect to the target "(gdb) target remote /dev/ttyS0".
|
|
||||||
|
|
||||||
10. Set software breakpoint "(gdb) break sys_open".
|
|
||||||
|
|
||||||
11. Continue "(gdb) c". Then enter Ctrl+C twice to stop GDB connection.
|
|
||||||
|
|
||||||
12. Run ls in the target console "/> ls". Dummy string can be seen on the console.
|
|
||||||
|
|
||||||
13. Then connect the gdb to target again. "(gdb) target remote /dev/ttyS0".
|
|
||||||
Now you will find a breakpoint is hit. "Breakpoint 1: sys_open(..."
|
|
||||||
|
|
||||||
14. All other operations are the same as that in KGDB over Ethernet. The only
|
|
||||||
difference is that after continue command in GDB, please stop GDB
|
|
||||||
connection by 2 "Ctrl+C"s and connect again after breakpoints are hit or
|
|
||||||
Ctrl+A is entered.
|
|
|
@ -246,7 +246,7 @@ will require extra work due to the application tag.
|
||||||
retrieve the tag buffer using bio_integrity_get_tag().
|
retrieve the tag buffer using bio_integrity_get_tag().
|
||||||
|
|
||||||
|
|
||||||
6.3 PASSING EXISTING INTEGRITY METADATA
|
5.3 PASSING EXISTING INTEGRITY METADATA
|
||||||
|
|
||||||
Filesystems that either generate their own integrity metadata or
|
Filesystems that either generate their own integrity metadata or
|
||||||
are capable of transferring IMD from user space can use the
|
are capable of transferring IMD from user space can use the
|
||||||
|
@ -283,7 +283,7 @@ will require extra work due to the application tag.
|
||||||
integrity upon completion.
|
integrity upon completion.
|
||||||
|
|
||||||
|
|
||||||
6.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
|
5.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
|
||||||
METADATA
|
METADATA
|
||||||
|
|
||||||
To enable integrity exchange on a block device the gendisk must be
|
To enable integrity exchange on a block device the gendisk must be
|
||||||
|
|
|
@ -30,12 +30,18 @@ write_expire (in ms)
|
||||||
Similar to read_expire mentioned above, but for writes.
|
Similar to read_expire mentioned above, but for writes.
|
||||||
|
|
||||||
|
|
||||||
fifo_batch
|
fifo_batch (number of requests)
|
||||||
----------
|
----------
|
||||||
|
|
||||||
When a read request expires its deadline, we must move some requests from
|
Requests are grouped into ``batches'' of a particular data direction (read or
|
||||||
the sorted io scheduler list to the block device dispatch queue. fifo_batch
|
write) which are serviced in increasing sector order. To limit extra seeking,
|
||||||
controls how many requests we move.
|
deadline expiries are only checked between batches. fifo_batch controls the
|
||||||
|
maximum number of requests per batch.
|
||||||
|
|
||||||
|
This parameter tunes the balance between per-request latency and aggregate
|
||||||
|
throughput. When low latency is the primary concern, smaller is better (where
|
||||||
|
a value of 1 yields first-come first-served behaviour). Increasing fifo_batch
|
||||||
|
generally improves throughput, at the cost of latency variation.
|
||||||
|
|
||||||
|
|
||||||
writes_starved (number of dispatches)
|
writes_starved (number of dispatches)
|
||||||
|
|
|
@ -145,8 +145,7 @@ useful for reading photocds.
|
||||||
|
|
||||||
To play an audio CD, you should first unmount and remove any data
|
To play an audio CD, you should first unmount and remove any data
|
||||||
CDROM. Any of the CDROM player programs should then work (workman,
|
CDROM. Any of the CDROM player programs should then work (workman,
|
||||||
workbone, cdplayer, etc.). Lacking anything else, you could use the
|
workbone, cdplayer, etc.).
|
||||||
cdtester program in Documentation/cdrom/sbpcd.
|
|
||||||
|
|
||||||
On a few drives, you can read digital audio directly using a program
|
On a few drives, you can read digital audio directly using a program
|
||||||
such as cdda2wav. The only types of drive which I've heard support
|
such as cdda2wav. The only types of drive which I've heard support
|
||||||
|
|
|
@ -0,0 +1,99 @@
|
||||||
|
The cgroup freezer is useful to batch job management system which start
|
||||||
|
and stop sets of tasks in order to schedule the resources of a machine
|
||||||
|
according to the desires of a system administrator. This sort of program
|
||||||
|
is often used on HPC clusters to schedule access to the cluster as a
|
||||||
|
whole. The cgroup freezer uses cgroups to describe the set of tasks to
|
||||||
|
be started/stopped by the batch job management system. It also provides
|
||||||
|
a means to start and stop the tasks composing the job.
|
||||||
|
|
||||||
|
The cgroup freezer will also be useful for checkpointing running groups
|
||||||
|
of tasks. The freezer allows the checkpoint code to obtain a consistent
|
||||||
|
image of the tasks by attempting to force the tasks in a cgroup into a
|
||||||
|
quiescent state. Once the tasks are quiescent another task can
|
||||||
|
walk /proc or invoke a kernel interface to gather information about the
|
||||||
|
quiesced tasks. Checkpointed tasks can be restarted later should a
|
||||||
|
recoverable error occur. This also allows the checkpointed tasks to be
|
||||||
|
migrated between nodes in a cluster by copying the gathered information
|
||||||
|
to another node and restarting the tasks there.
|
||||||
|
|
||||||
|
Sequences of SIGSTOP and SIGCONT are not always sufficient for stopping
|
||||||
|
and resuming tasks in userspace. Both of these signals are observable
|
||||||
|
from within the tasks we wish to freeze. While SIGSTOP cannot be caught,
|
||||||
|
blocked, or ignored it can be seen by waiting or ptracing parent tasks.
|
||||||
|
SIGCONT is especially unsuitable since it can be caught by the task. Any
|
||||||
|
programs designed to watch for SIGSTOP and SIGCONT could be broken by
|
||||||
|
attempting to use SIGSTOP and SIGCONT to stop and resume tasks. We can
|
||||||
|
demonstrate this problem using nested bash shells:
|
||||||
|
|
||||||
|
$ echo $$
|
||||||
|
16644
|
||||||
|
$ bash
|
||||||
|
$ echo $$
|
||||||
|
16690
|
||||||
|
|
||||||
|
From a second, unrelated bash shell:
|
||||||
|
$ kill -SIGSTOP 16690
|
||||||
|
$ kill -SIGCONT 16990
|
||||||
|
|
||||||
|
<at this point 16990 exits and causes 16644 to exit too>
|
||||||
|
|
||||||
|
This happens because bash can observe both signals and choose how it
|
||||||
|
responds to them.
|
||||||
|
|
||||||
|
Another example of a program which catches and responds to these
|
||||||
|
signals is gdb. In fact any program designed to use ptrace is likely to
|
||||||
|
have a problem with this method of stopping and resuming tasks.
|
||||||
|
|
||||||
|
In contrast, the cgroup freezer uses the kernel freezer code to
|
||||||
|
prevent the freeze/unfreeze cycle from becoming visible to the tasks
|
||||||
|
being frozen. This allows the bash example above and gdb to run as
|
||||||
|
expected.
|
||||||
|
|
||||||
|
The freezer subsystem in the container filesystem defines a file named
|
||||||
|
freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the
|
||||||
|
cgroup. Subsequently writing "THAWED" will unfreeze the tasks in the cgroup.
|
||||||
|
Reading will return the current state.
|
||||||
|
|
||||||
|
* Examples of usage :
|
||||||
|
|
||||||
|
# mkdir /containers/freezer
|
||||||
|
# mount -t cgroup -ofreezer freezer /containers
|
||||||
|
# mkdir /containers/0
|
||||||
|
# echo $some_pid > /containers/0/tasks
|
||||||
|
|
||||||
|
to get status of the freezer subsystem :
|
||||||
|
|
||||||
|
# cat /containers/0/freezer.state
|
||||||
|
THAWED
|
||||||
|
|
||||||
|
to freeze all tasks in the container :
|
||||||
|
|
||||||
|
# echo FROZEN > /containers/0/freezer.state
|
||||||
|
# cat /containers/0/freezer.state
|
||||||
|
FREEZING
|
||||||
|
# cat /containers/0/freezer.state
|
||||||
|
FROZEN
|
||||||
|
|
||||||
|
to unfreeze all tasks in the container :
|
||||||
|
|
||||||
|
# echo THAWED > /containers/0/freezer.state
|
||||||
|
# cat /containers/0/freezer.state
|
||||||
|
THAWED
|
||||||
|
|
||||||
|
This is the basic mechanism which should do the right thing for user space task
|
||||||
|
in a simple scenario.
|
||||||
|
|
||||||
|
It's important to note that freezing can be incomplete. In that case we return
|
||||||
|
EBUSY. This means that some tasks in the cgroup are busy doing something that
|
||||||
|
prevents us from completely freezing the cgroup at this time. After EBUSY,
|
||||||
|
the cgroup will remain partially frozen -- reflected by freezer.state reporting
|
||||||
|
"FREEZING" when read. The state will remain "FREEZING" until one of these
|
||||||
|
things happens:
|
||||||
|
|
||||||
|
1) Userspace cancels the freezing operation by writing "THAWED" to
|
||||||
|
the freezer.state file
|
||||||
|
2) Userspace retries the freezing operation by writing "FROZEN" to
|
||||||
|
the freezer.state file (writing "FREEZING" is not legal
|
||||||
|
and returns EIO)
|
||||||
|
3) The tasks that blocked the cgroup from entering the "FROZEN"
|
||||||
|
state disappear from the cgroup's set of tasks.
|
|
@ -112,14 +112,22 @@ the per cgroup LRU.
|
||||||
|
|
||||||
2.2.1 Accounting details
|
2.2.1 Accounting details
|
||||||
|
|
||||||
All mapped pages (RSS) and unmapped user pages (Page Cache) are accounted.
|
All mapped anon pages (RSS) and cache pages (Page Cache) are accounted.
|
||||||
RSS pages are accounted at the time of page_add_*_rmap() unless they've already
|
(some pages which never be reclaimable and will not be on global LRU
|
||||||
been accounted for earlier. A file page will be accounted for as Page Cache;
|
are not accounted. we just accounts pages under usual vm management.)
|
||||||
it's mapped into the page tables of a process, duplicate accounting is carefully
|
|
||||||
avoided. Page Cache pages are accounted at the time of add_to_page_cache().
|
RSS pages are accounted at page_fault unless they've already been accounted
|
||||||
The corresponding routines that remove a page from the page tables or removes
|
for earlier. A file page will be accounted for as Page Cache when it's
|
||||||
a page from Page Cache is used to decrement the accounting counters of the
|
inserted into inode (radix-tree). While it's mapped into the page tables of
|
||||||
cgroup.
|
processes, duplicate accounting is carefully avoided.
|
||||||
|
|
||||||
|
A RSS page is unaccounted when it's fully unmapped. A PageCache page is
|
||||||
|
unaccounted when it's removed from radix-tree.
|
||||||
|
|
||||||
|
At page migration, accounting information is kept.
|
||||||
|
|
||||||
|
Note: we just account pages-on-lru because our purpose is to control amount
|
||||||
|
of used pages. not-on-lru pages are tend to be out-of-control from vm view.
|
||||||
|
|
||||||
2.3 Shared Page Accounting
|
2.3 Shared Page Accounting
|
||||||
|
|
||||||
|
|
|
@ -48,7 +48,7 @@ hooks, beyond what is already present, required to manage dynamic
|
||||||
job placement on large systems.
|
job placement on large systems.
|
||||||
|
|
||||||
Cpusets use the generic cgroup subsystem described in
|
Cpusets use the generic cgroup subsystem described in
|
||||||
Documentation/cgroup.txt.
|
Documentation/cgroups/cgroups.txt.
|
||||||
|
|
||||||
Requests by a task, using the sched_setaffinity(2) system call to
|
Requests by a task, using the sched_setaffinity(2) system call to
|
||||||
include CPUs in its CPU affinity mask, and using the mbind(2) and
|
include CPUs in its CPU affinity mask, and using the mbind(2) and
|
||||||
|
|
|
@ -27,7 +27,7 @@ operating system.
|
||||||
The ETRAX 100LX chip
|
The ETRAX 100LX chip
|
||||||
--------------------
|
--------------------
|
||||||
|
|
||||||
For reference, plase see the press-release:
|
For reference, please see the press-release:
|
||||||
|
|
||||||
http://www.axis.com/news/us/001101_etrax.htm
|
http://www.axis.com/news/us/001101_etrax.htm
|
||||||
|
|
||||||
|
|
|
@ -0,0 +1,274 @@
|
||||||
|
1: A GUIDE TO THE KERNEL DEVELOPMENT PROCESS
|
||||||
|
|
||||||
|
The purpose of this document is to help developers (and their managers)
|
||||||
|
work with the development community with a minimum of frustration. It is
|
||||||
|
an attempt to document how this community works in a way which is
|
||||||
|
accessible to those who are not intimately familiar with Linux kernel
|
||||||
|
development (or, indeed, free software development in general). While
|
||||||
|
there is some technical material here, this is very much a process-oriented
|
||||||
|
discussion which does not require a deep knowledge of kernel programming to
|
||||||
|
understand.
|
||||||
|
|
||||||
|
|
||||||
|
1.1: EXECUTIVE SUMMARY
|
||||||
|
|
||||||
|
The rest of this section covers the scope of the kernel development process
|
||||||
|
and the kinds of frustrations that developers and their employers can
|
||||||
|
encounter there. There are a great many reasons why kernel code should be
|
||||||
|
merged into the official ("mainline") kernel, including automatic
|
||||||
|
availability to users, community support in many forms, and the ability to
|
||||||
|
influence the direction of kernel development. Code contributed to the
|
||||||
|
Linux kernel must be made available under a GPL-compatible license.
|
||||||
|
|
||||||
|
Section 2 introduces the development process, the kernel release cycle, and
|
||||||
|
the mechanics of the merge window. The various phases in the patch
|
||||||
|
development, review, and merging cycle are covered. There is some
|
||||||
|
discussion of tools and mailing lists. Developers wanting to get started
|
||||||
|
with kernel development are encouraged to track down and fix bugs as an
|
||||||
|
initial exercise.
|
||||||
|
|
||||||
|
Section 3 covers early-stage project planning, with an emphasis on
|
||||||
|
involving the development community as soon as possible.
|
||||||
|
|
||||||
|
Section 4 is about the coding process; several pitfalls which have been
|
||||||
|
encountered by other developers are discussed. Some requirements for
|
||||||
|
patches are covered, and there is an introduction to some of the tools
|
||||||
|
which can help to ensure that kernel patches are correct.
|
||||||
|
|
||||||
|
Section 5 talks about the process of posting patches for review. To be
|
||||||
|
taken seriously by the development community, patches must be properly
|
||||||
|
formatted and described, and they must be sent to the right place.
|
||||||
|
Following the advice in this section should help to ensure the best
|
||||||
|
possible reception for your work.
|
||||||
|
|
||||||
|
Section 6 covers what happens after posting patches; the job is far from
|
||||||
|
done at that point. Working with reviewers is a crucial part of the
|
||||||
|
development process; this section offers a number of tips on how to avoid
|
||||||
|
problems at this important stage. Developers are cautioned against
|
||||||
|
assuming that the job is done when a patch is merged into the mainline.
|
||||||
|
|
||||||
|
Section 7 introduces a couple of "advanced" topics: managing patches with
|
||||||
|
git and reviewing patches posted by others.
|
||||||
|
|
||||||
|
Section 8 concludes the document with pointers to sources for more
|
||||||
|
information on kernel development.
|
||||||
|
|
||||||
|
|
||||||
|
1.2: WHAT THIS DOCUMENT IS ABOUT
|
||||||
|
|
||||||
|
The Linux kernel, at over 6 million lines of code and well over 1000 active
|
||||||
|
contributors, is one of the largest and most active free software projects
|
||||||
|
in existence. Since its humble beginning in 1991, this kernel has evolved
|
||||||
|
into a best-of-breed operating system component which runs on pocket-sized
|
||||||
|
digital music players, desktop PCs, the largest supercomputers in
|
||||||
|
existence, and all types of systems in between. It is a robust, efficient,
|
||||||
|
and scalable solution for almost any situation.
|
||||||
|
|
||||||
|
With the growth of Linux has come an increase in the number of developers
|
||||||
|
(and companies) wishing to participate in its development. Hardware
|
||||||
|
vendors want to ensure that Linux supports their products well, making
|
||||||
|
those products attractive to Linux users. Embedded systems vendors, who
|
||||||
|
use Linux as a component in an integrated product, want Linux to be as
|
||||||
|
capable and well-suited to the task at hand as possible. Distributors and
|
||||||
|
other software vendors who base their products on Linux have a clear
|
||||||
|
interest in the capabilities, performance, and reliability of the Linux
|
||||||
|
kernel. And end users, too, will often wish to change Linux to make it
|
||||||
|
better suit their needs.
|
||||||
|
|
||||||
|
One of the most compelling features of Linux is that it is accessible to
|
||||||
|
these developers; anybody with the requisite skills can improve Linux and
|
||||||
|
influence the direction of its development. Proprietary products cannot
|
||||||
|
offer this kind of openness, which is a characteristic of the free software
|
||||||
|
process. But, if anything, the kernel is even more open than most other
|
||||||
|
free software projects. A typical three-month kernel development cycle can
|
||||||
|
involve over 1000 developers working for more than 100 different companies
|
||||||
|
(or for no company at all).
|
||||||
|
|
||||||
|
Working with the kernel development community is not especially hard. But,
|
||||||
|
that notwithstanding, many potential contributors have experienced
|
||||||
|
difficulties when trying to do kernel work. The kernel community has
|
||||||
|
evolved its own distinct ways of operating which allow it to function
|
||||||
|
smoothly (and produce a high-quality product) in an environment where
|
||||||
|
thousands of lines of code are being changed every day. So it is not
|
||||||
|
surprising that Linux kernel development process differs greatly from
|
||||||
|
proprietary development methods.
|
||||||
|
|
||||||
|
The kernel's development process may come across as strange and
|
||||||
|
intimidating to new developers, but there are good reasons and solid
|
||||||
|
experience behind it. A developer who does not understand the kernel
|
||||||
|
community's ways (or, worse, who tries to flout or circumvent them) will
|
||||||
|
have a frustrating experience in store. The development community, while
|
||||||
|
being helpful to those who are trying to learn, has little time for those
|
||||||
|
who will not listen or who do not care about the development process.
|
||||||
|
|
||||||
|
It is hoped that those who read this document will be able to avoid that
|
||||||
|
frustrating experience. There is a lot of material here, but the effort
|
||||||
|
involved in reading it will be repaid in short order. The development
|
||||||
|
community is always in need of developers who will help to make the kernel
|
||||||
|
better; the following text should help you - or those who work for you -
|
||||||
|
join our community.
|
||||||
|
|
||||||
|
|
||||||
|
1.3: CREDITS
|
||||||
|
|
||||||
|
This document was written by Jonathan Corbet, corbet@lwn.net. It has been
|
||||||
|
improved by comments from Johannes Berg, James Berry, Alex Chiang, Roland
|
||||||
|
Dreier, Randy Dunlap, Jake Edge, Jiri Kosina, Matt Mackall, Arthur Marsh,
|
||||||
|
Amanda McPherson, Andrew Morton, Andrew Price, Tsugikazu Shibata, and
|
||||||
|
Jochen Voß.
|
||||||
|
|
||||||
|
This work was supported by the Linux Foundation; thanks especially to
|
||||||
|
Amanda McPherson, who saw the value of this effort and made it all happen.
|
||||||
|
|
||||||
|
|
||||||
|
1.4: THE IMPORTANCE OF GETTING CODE INTO THE MAINLINE
|
||||||
|
|
||||||
|
Some companies and developers occasionally wonder why they should bother
|
||||||
|
learning how to work with the kernel community and get their code into the
|
||||||
|
mainline kernel (the "mainline" being the kernel maintained by Linus
|
||||||
|
Torvalds and used as a base by Linux distributors). In the short term,
|
||||||
|
contributing code can look like an avoidable expense; it seems easier to
|
||||||
|
just keep the code separate and support users directly. The truth of the
|
||||||
|
matter is that keeping code separate ("out of tree") is a false economy.
|
||||||
|
|
||||||
|
As a way of illustrating the costs of out-of-tree code, here are a few
|
||||||
|
relevant aspects of the kernel development process; most of these will be
|
||||||
|
discussed in greater detail later in this document. Consider:
|
||||||
|
|
||||||
|
- Code which has been merged into the mainline kernel is available to all
|
||||||
|
Linux users. It will automatically be present on all distributions which
|
||||||
|
enable it. There is no need for driver disks, downloads, or the hassles
|
||||||
|
of supporting multiple versions of multiple distributions; it all just
|
||||||
|
works, for the developer and for the user. Incorporation into the
|
||||||
|
mainline solves a large number of distribution and support problems.
|
||||||
|
|
||||||
|
- While kernel developers strive to maintain a stable interface to user
|
||||||
|
space, the internal kernel API is in constant flux. The lack of a stable
|
||||||
|
internal interface is a deliberate design decision; it allows fundamental
|
||||||
|
improvements to be made at any time and results in higher-quality code.
|
||||||
|
But one result of that policy is that any out-of-tree code requires
|
||||||
|
constant upkeep if it is to work with new kernels. Maintaining
|
||||||
|
out-of-tree code requires significant amounts of work just to keep that
|
||||||
|
code working.
|
||||||
|
|
||||||
|
Code which is in the mainline, instead, does not require this work as the
|
||||||
|
result of a simple rule requiring any developer who makes an API change
|
||||||
|
to also fix any code that breaks as the result of that change. So code
|
||||||
|
which has been merged into the mainline has significantly lower
|
||||||
|
maintenance costs.
|
||||||
|
|
||||||
|
- Beyond that, code which is in the kernel will often be improved by other
|
||||||
|
developers. Surprising results can come from empowering your user
|
||||||
|
community and customers to improve your product.
|
||||||
|
|
||||||
|
- Kernel code is subjected to review, both before and after merging into
|
||||||
|
the mainline. No matter how strong the original developer's skills are,
|
||||||
|
this review process invariably finds ways in which the code can be
|
||||||
|
improved. Often review finds severe bugs and security problems. This is
|
||||||
|
especially true for code which has been developed in a closed
|
||||||
|
environment; such code benefits strongly from review by outside
|
||||||
|
developers. Out-of-tree code is lower-quality code.
|
||||||
|
|
||||||
|
- Participation in the development process is your way to influence the
|
||||||
|
direction of kernel development. Users who complain from the sidelines
|
||||||
|
are heard, but active developers have a stronger voice - and the ability
|
||||||
|
to implement changes which make the kernel work better for their needs.
|
||||||
|
|
||||||
|
- When code is maintained separately, the possibility that a third party
|
||||||
|
will contribute a different implementation of a similar feature always
|
||||||
|
exists. Should that happen, getting your code merged will become much
|
||||||
|
harder - to the point of impossibility. Then you will be faced with the
|
||||||
|
unpleasant alternatives of either (1) maintaining a nonstandard feature
|
||||||
|
out of tree indefinitely, or (2) abandoning your code and migrating your
|
||||||
|
users over to the in-tree version.
|
||||||
|
|
||||||
|
- Contribution of code is the fundamental action which makes the whole
|
||||||
|
process work. By contributing your code you can add new functionality to
|
||||||
|
the kernel and provide capabilities and examples which are of use to
|
||||||
|
other kernel developers. If you have developed code for Linux (or are
|
||||||
|
thinking about doing so), you clearly have an interest in the continued
|
||||||
|
success of this platform; contributing code is one of the best ways to
|
||||||
|
help ensure that success.
|
||||||
|
|
||||||
|
All of the reasoning above applies to any out-of-tree kernel code,
|
||||||
|
including code which is distributed in proprietary, binary-only form.
|
||||||
|
There are, however, additional factors which should be taken into account
|
||||||
|
before considering any sort of binary-only kernel code distribution. These
|
||||||
|
include:
|
||||||
|
|
||||||
|
- The legal issues around the distribution of proprietary kernel modules
|
||||||
|
are cloudy at best; quite a few kernel copyright holders believe that
|
||||||
|
most binary-only modules are derived products of the kernel and that, as
|
||||||
|
a result, their distribution is a violation of the GNU General Public
|
||||||
|
license (about which more will be said below). Your author is not a
|
||||||
|
lawyer, and nothing in this document can possibly be considered to be
|
||||||
|
legal advice. The true legal status of closed-source modules can only be
|
||||||
|
determined by the courts. But the uncertainty which haunts those modules
|
||||||
|
is there regardless.
|
||||||
|
|
||||||
|
- Binary modules greatly increase the difficulty of debugging kernel
|
||||||
|
problems, to the point that most kernel developers will not even try. So
|
||||||
|
the distribution of binary-only modules will make it harder for your
|
||||||
|
users to get support from the community.
|
||||||
|
|
||||||
|
- Support is also harder for distributors of binary-only modules, who must
|
||||||
|
provide a version of the module for every distribution and every kernel
|
||||||
|
version they wish to support. Dozens of builds of a single module can
|
||||||
|
be required to provide reasonably comprehensive coverage, and your users
|
||||||
|
will have to upgrade your module separately every time they upgrade their
|
||||||
|
kernel.
|
||||||
|
|
||||||
|
- Everything that was said above about code review applies doubly to
|
||||||
|
closed-source code. Since this code is not available at all, it cannot
|
||||||
|
have been reviewed by the community and will, beyond doubt, have serious
|
||||||
|
problems.
|
||||||
|
|
||||||
|
Makers of embedded systems, in particular, may be tempted to disregard much
|
||||||
|
of what has been said in this section in the belief that they are shipping
|
||||||
|
a self-contained product which uses a frozen kernel version and requires no
|
||||||
|
more development after its release. This argument misses the value of
|
||||||
|
widespread code review and the value of allowing your users to add
|
||||||
|
capabilities to your product. But these products, too, have a limited
|
||||||
|
commercial life, after which a new version must be released. At that
|
||||||
|
point, vendors whose code is in the mainline and well maintained will be
|
||||||
|
much better positioned to get the new product ready for market quickly.
|
||||||
|
|
||||||
|
|
||||||
|
1.5: LICENSING
|
||||||
|
|
||||||
|
Code is contributed to the Linux kernel under a number of licenses, but all
|
||||||
|
code must be compatible with version 2 of the GNU General Public License
|
||||||
|
(GPLv2), which is the license covering the kernel distribution as a whole.
|
||||||
|
In practice, that means that all code contributions are covered either by
|
||||||
|
GPLv2 (with, optionally, language allowing distribution under later
|
||||||
|
versions of the GPL) or the three-clause BSD license. Any contributions
|
||||||
|
which are not covered by a compatible license will not be accepted into the
|
||||||
|
kernel.
|
||||||
|
|
||||||
|
Copyright assignments are not required (or requested) for code contributed
|
||||||
|
to the kernel. All code merged into the mainline kernel retains its
|
||||||
|
original ownership; as a result, the kernel now has thousands of owners.
|
||||||
|
|
||||||
|
One implication of this ownership structure is that any attempt to change
|
||||||
|
the licensing of the kernel is doomed to almost certain failure. There are
|
||||||
|
few practical scenarios where the agreement of all copyright holders could
|
||||||
|
be obtained (or their code removed from the kernel). So, in particular,
|
||||||
|
there is no prospect of a migration to version 3 of the GPL in the
|
||||||
|
foreseeable future.
|
||||||
|
|
||||||
|
It is imperative that all code contributed to the kernel be legitimately
|
||||||
|
free software. For that reason, code from anonymous (or pseudonymous)
|
||||||
|
contributors will not be accepted. All contributors are required to "sign
|
||||||
|
off" on their code, stating that the code can be distributed with the
|
||||||
|
kernel under the GPL. Code which has not been licensed as free software by
|
||||||
|
its owner, or which risks creating copyright-related problems for the
|
||||||
|
kernel (such as code which derives from reverse-engineering efforts lacking
|
||||||
|
proper safeguards) cannot be contributed.
|
||||||
|
|
||||||
|
Questions about copyright-related issues are common on Linux development
|
||||||
|
mailing lists. Such questions will normally receive no shortage of
|
||||||
|
answers, but one should bear in mind that the people answering those
|
||||||
|
questions are not lawyers and cannot provide legal advice. If you have
|
||||||
|
legal questions relating to Linux source code, there is no substitute for
|
||||||
|
talking with a lawyer who understands this field. Relying on answers
|
||||||
|
obtained on technical mailing lists is a risky affair.
|
|
@ -0,0 +1,459 @@
|
||||||
|
2: HOW THE DEVELOPMENT PROCESS WORKS
|
||||||
|
|
||||||
|
Linux kernel development in the early 1990's was a pretty loose affair,
|
||||||
|
with relatively small numbers of users and developers involved. With a
|
||||||
|
user base in the millions and with some 2,000 developers involved over the
|
||||||
|
course of one year, the kernel has since had to evolve a number of
|
||||||
|
processes to keep development happening smoothly. A solid understanding of
|
||||||
|
how the process works is required in order to be an effective part of it.
|
||||||
|
|
||||||
|
|
||||||
|
2.1: THE BIG PICTURE
|
||||||
|
|
||||||
|
The kernel developers use a loosely time-based release process, with a new
|
||||||
|
major kernel release happening every two or three months. The recent
|
||||||
|
release history looks like this:
|
||||||
|
|
||||||
|
2.6.26 July 13, 2008
|
||||||
|
2.6.25 April 16, 2008
|
||||||
|
2.6.24 January 24, 2008
|
||||||
|
2.6.23 October 9, 2007
|
||||||
|
2.6.22 July 8, 2007
|
||||||
|
2.6.21 April 25, 2007
|
||||||
|
2.6.20 February 4, 2007
|
||||||
|
|
||||||
|
Every 2.6.x release is a major kernel release with new features, internal
|
||||||
|
API changes, and more. A typical 2.6 release can contain over 10,000
|
||||||
|
changesets with changes to several hundred thousand lines of code. 2.6 is
|
||||||
|
thus the leading edge of Linux kernel development; the kernel uses a
|
||||||
|
rolling development model which is continually integrating major changes.
|
||||||
|
|
||||||
|
A relatively straightforward discipline is followed with regard to the
|
||||||
|
merging of patches for each release. At the beginning of each development
|
||||||
|
cycle, the "merge window" is said to be open. At that time, code which is
|
||||||
|
deemed to be sufficiently stable (and which is accepted by the development
|
||||||
|
community) is merged into the mainline kernel. The bulk of changes for a
|
||||||
|
new development cycle (and all of the major changes) will be merged during
|
||||||
|
this time, at a rate approaching 1,000 changes ("patches," or "changesets")
|
||||||
|
per day.
|
||||||
|
|
||||||
|
(As an aside, it is worth noting that the changes integrated during the
|
||||||
|
merge window do not come out of thin air; they have been collected, tested,
|
||||||
|
and staged ahead of time. How that process works will be described in
|
||||||
|
detail later on).
|
||||||
|
|
||||||
|
The merge window lasts for two weeks. At the end of this time, Linus
|
||||||
|
Torvalds will declare that the window is closed and release the first of
|
||||||
|
the "rc" kernels. For the kernel which is destined to be 2.6.26, for
|
||||||
|
example, the release which happens at the end of the merge window will be
|
||||||
|
called 2.6.26-rc1. The -rc1 release is the signal that the time to merge
|
||||||
|
new features has passed, and that the time to stabilize the next kernel has
|
||||||
|
begun.
|
||||||
|
|
||||||
|
Over the next six to ten weeks, only patches which fix problems should be
|
||||||
|
submitted to the mainline. On occasion a more significant change will be
|
||||||
|
allowed, but such occasions are rare; developers who try to merge new
|
||||||
|
features outside of the merge window tend to get an unfriendly reception.
|
||||||
|
As a general rule, if you miss the merge window for a given feature, the
|
||||||
|
best thing to do is to wait for the next development cycle. (An occasional
|
||||||
|
exception is made for drivers for previously-unsupported hardware; if they
|
||||||
|
touch no in-tree code, they cannot cause regressions and should be safe to
|
||||||
|
add at any time).
|
||||||
|
|
||||||
|
As fixes make their way into the mainline, the patch rate will slow over
|
||||||
|
time. Linus releases new -rc kernels about once a week; a normal series
|
||||||
|
will get up to somewhere between -rc6 and -rc9 before the kernel is
|
||||||
|
considered to be sufficiently stable and the final 2.6.x release is made.
|
||||||
|
At that point the whole process starts over again.
|
||||||
|
|
||||||
|
As an example, here is how the 2.6.25 development cycle went (all dates in
|
||||||
|
2008):
|
||||||
|
|
||||||
|
January 24 2.6.24 stable release
|
||||||
|
February 10 2.6.25-rc1, merge window closes
|
||||||
|
February 15 2.6.25-rc2
|
||||||
|
February 24 2.6.25-rc3
|
||||||
|
March 4 2.6.25-rc4
|
||||||
|
March 9 2.6.25-rc5
|
||||||
|
March 16 2.6.25-rc6
|
||||||
|
March 25 2.6.25-rc7
|
||||||
|
April 1 2.6.25-rc8
|
||||||
|
April 11 2.6.25-rc9
|
||||||
|
April 16 2.6.25 stable release
|
||||||
|
|
||||||
|
How do the developers decide when to close the development cycle and create
|
||||||
|
the stable release? The most significant metric used is the list of
|
||||||
|
regressions from previous releases. No bugs are welcome, but those which
|
||||||
|
break systems which worked in the past are considered to be especially
|
||||||
|
serious. For this reason, patches which cause regressions are looked upon
|
||||||
|
unfavorably and are quite likely to be reverted during the stabilization
|
||||||
|
period.
|
||||||
|
|
||||||
|
The developers' goal is to fix all known regressions before the stable
|
||||||
|
release is made. In the real world, this kind of perfection is hard to
|
||||||
|
achieve; there are just too many variables in a project of this size.
|
||||||
|
There comes a point where delaying the final release just makes the problem
|
||||||
|
worse; the pile of changes waiting for the next merge window will grow
|
||||||
|
larger, creating even more regressions the next time around. So most 2.6.x
|
||||||
|
kernels go out with a handful of known regressions though, hopefully, none
|
||||||
|
of them are serious.
|
||||||
|
|
||||||
|
Once a stable release is made, its ongoing maintenance is passed off to the
|
||||||
|
"stable team," currently comprised of Greg Kroah-Hartman and Chris Wright.
|
||||||
|
The stable team will release occasional updates to the stable release using
|
||||||
|
the 2.6.x.y numbering scheme. To be considered for an update release, a
|
||||||
|
patch must (1) fix a significant bug, and (2) already be merged into the
|
||||||
|
mainline for the next development kernel. Continuing our 2.6.25 example,
|
||||||
|
the history (as of this writing) is:
|
||||||
|
|
||||||
|
May 1 2.6.25.1
|
||||||
|
May 6 2.6.25.2
|
||||||
|
May 9 2.6.25.3
|
||||||
|
May 15 2.6.25.4
|
||||||
|
June 7 2.6.25.5
|
||||||
|
June 9 2.6.25.6
|
||||||
|
June 16 2.6.25.7
|
||||||
|
June 21 2.6.25.8
|
||||||
|
June 24 2.6.25.9
|
||||||
|
|
||||||
|
Stable updates for a given kernel are made for approximately six months;
|
||||||
|
after that, the maintenance of stable releases is solely the responsibility
|
||||||
|
of the distributors which have shipped that particular kernel.
|
||||||
|
|
||||||
|
|
||||||
|
2.2: THE LIFECYCLE OF A PATCH
|
||||||
|
|
||||||
|
Patches do not go directly from the developer's keyboard into the mainline
|
||||||
|
kernel. There is, instead, a somewhat involved (if somewhat informal)
|
||||||
|
process designed to ensure that each patch is reviewed for quality and that
|
||||||
|
each patch implements a change which is desirable to have in the mainline.
|
||||||
|
This process can happen quickly for minor fixes, or, in the case of large
|
||||||
|
and controversial changes, go on for years. Much developer frustration
|
||||||
|
comes from a lack of understanding of this process or from attempts to
|
||||||
|
circumvent it.
|
||||||
|
|
||||||
|
In the hopes of reducing that frustration, this document will describe how
|
||||||
|
a patch gets into the kernel. What follows below is an introduction which
|
||||||
|
describes the process in a somewhat idealized way. A much more detailed
|
||||||
|
treatment will come in later sections.
|
||||||
|
|
||||||
|
The stages that a patch goes through are, generally:
|
||||||
|
|
||||||
|
- Design. This is where the real requirements for the patch - and the way
|
||||||
|
those requirements will be met - are laid out. Design work is often
|
||||||
|
done without involving the community, but it is better to do this work
|
||||||
|
in the open if at all possible; it can save a lot of time redesigning
|
||||||
|
things later.
|
||||||
|
|
||||||
|
- Early review. Patches are posted to the relevant mailing list, and
|
||||||
|
developers on that list reply with any comments they may have. This
|
||||||
|
process should turn up any major problems with a patch if all goes
|
||||||
|
well.
|
||||||
|
|
||||||
|
- Wider review. When the patch is getting close to ready for mainline
|
||||||
|
inclusion, it will be accepted by a relevant subsystem maintainer -
|
||||||
|
though this acceptance is not a guarantee that the patch will make it
|
||||||
|
all the way to the mainline. The patch will show up in the maintainer's
|
||||||
|
subsystem tree and into the staging trees (described below). When the
|
||||||
|
process works, this step leads to more extensive review of the patch and
|
||||||
|
the discovery of any problems resulting from the integration of this
|
||||||
|
patch with work being done by others.
|
||||||
|
|
||||||
|
- Merging into the mainline. Eventually, a successful patch will be
|
||||||
|
merged into the mainline repository managed by Linus Torvalds. More
|
||||||
|
comments and/or problems may surface at this time; it is important that
|
||||||
|
the developer be responsive to these and fix any issues which arise.
|
||||||
|
|
||||||
|
- Stable release. The number of users potentially affected by the patch
|
||||||
|
is now large, so, once again, new problems may arise.
|
||||||
|
|
||||||
|
- Long-term maintenance. While it is certainly possible for a developer
|
||||||
|
to forget about code after merging it, that sort of behavior tends to
|
||||||
|
leave a poor impression in the development community. Merging code
|
||||||
|
eliminates some of the maintenance burden, in that others will fix
|
||||||
|
problems caused by API changes. But the original developer should
|
||||||
|
continue to take responsibility for the code if it is to remain useful
|
||||||
|
in the longer term.
|
||||||
|
|
||||||
|
One of the largest mistakes made by kernel developers (or their employers)
|
||||||
|
is to try to cut the process down to a single "merging into the mainline"
|
||||||
|
step. This approach invariably leads to frustration for everybody
|
||||||
|
involved.
|
||||||
|
|
||||||
|
|
||||||
|
2.3: HOW PATCHES GET INTO THE KERNEL
|
||||||
|
|
||||||
|
There is exactly one person who can merge patches into the mainline kernel
|
||||||
|
repository: Linus Torvalds. But, of the over 12,000 patches which went
|
||||||
|
into the 2.6.25 kernel, only 250 (around 2%) were directly chosen by Linus
|
||||||
|
himself. The kernel project has long since grown to a size where no single
|
||||||
|
developer could possibly inspect and select every patch unassisted. The
|
||||||
|
way the kernel developers have addressed this growth is through the use of
|
||||||
|
a lieutenant system built around a chain of trust.
|
||||||
|
|
||||||
|
The kernel code base is logically broken down into a set of subsystems:
|
||||||
|
networking, specific architecture support, memory management, video
|
||||||
|
devices, etc. Most subsystems have a designated maintainer, a developer
|
||||||
|
who has overall responsibility for the code within that subsystem. These
|
||||||
|
subsystem maintainers are the gatekeepers (in a loose way) for the portion
|
||||||
|
of the kernel they manage; they are the ones who will (usually) accept a
|
||||||
|
patch for inclusion into the mainline kernel.
|
||||||
|
|
||||||
|
Subsystem maintainers each manage their own version of the kernel source
|
||||||
|
tree, usually (but certainly not always) using the git source management
|
||||||
|
tool. Tools like git (and related tools like quilt or mercurial) allow
|
||||||
|
maintainers to track a list of patches, including authorship information
|
||||||
|
and other metadata. At any given time, the maintainer can identify which
|
||||||
|
patches in his or her repository are not found in the mainline.
|
||||||
|
|
||||||
|
When the merge window opens, top-level maintainers will ask Linus to "pull"
|
||||||
|
the patches they have selected for merging from their repositories. If
|
||||||
|
Linus agrees, the stream of patches will flow up into his repository,
|
||||||
|
becoming part of the mainline kernel. The amount of attention that Linus
|
||||||
|
pays to specific patches received in a pull operation varies. It is clear
|
||||||
|
that, sometimes, he looks quite closely. But, as a general rule, Linus
|
||||||
|
trusts the subsystem maintainers to not send bad patches upstream.
|
||||||
|
|
||||||
|
Subsystem maintainers, in turn, can pull patches from other maintainers.
|
||||||
|
For example, the networking tree is built from patches which accumulated
|
||||||
|
first in trees dedicated to network device drivers, wireless networking,
|
||||||
|
etc. This chain of repositories can be arbitrarily long, though it rarely
|
||||||
|
exceeds two or three links. Since each maintainer in the chain trusts
|
||||||
|
those managing lower-level trees, this process is known as the "chain of
|
||||||
|
trust."
|
||||||
|
|
||||||
|
Clearly, in a system like this, getting patches into the kernel depends on
|
||||||
|
finding the right maintainer. Sending patches directly to Linus is not
|
||||||
|
normally the right way to go.
|
||||||
|
|
||||||
|
|
||||||
|
2.4: STAGING TREES
|
||||||
|
|
||||||
|
The chain of subsystem trees guides the flow of patches into the kernel,
|
||||||
|
but it also raises an interesting question: what if somebody wants to look
|
||||||
|
at all of the patches which are being prepared for the next merge window?
|
||||||
|
Developers will be interested in what other changes are pending to see
|
||||||
|
whether there are any conflicts to worry about; a patch which changes a
|
||||||
|
core kernel function prototype, for example, will conflict with any other
|
||||||
|
patches which use the older form of that function. Reviewers and testers
|
||||||
|
want access to the changes in their integrated form before all of those
|
||||||
|
changes land in the mainline kernel. One could pull changes from all of
|
||||||
|
the interesting subsystem trees, but that would be a big and error-prone
|
||||||
|
job.
|
||||||
|
|
||||||
|
The answer comes in the form of staging trees, where subsystem trees are
|
||||||
|
collected for testing and review. The older of these trees, maintained by
|
||||||
|
Andrew Morton, is called "-mm" (for memory management, which is how it got
|
||||||
|
started). The -mm tree integrates patches from a long list of subsystem
|
||||||
|
trees; it also has some patches aimed at helping with debugging.
|
||||||
|
|
||||||
|
Beyond that, -mm contains a significant collection of patches which have
|
||||||
|
been selected by Andrew directly. These patches may have been posted on a
|
||||||
|
mailing list, or they may apply to a part of the kernel for which there is
|
||||||
|
no designated subsystem tree. As a result, -mm operates as a sort of
|
||||||
|
subsystem tree of last resort; if there is no other obvious path for a
|
||||||
|
patch into the mainline, it is likely to end up in -mm. Miscellaneous
|
||||||
|
patches which accumulate in -mm will eventually either be forwarded on to
|
||||||
|
an appropriate subsystem tree or be sent directly to Linus. In a typical
|
||||||
|
development cycle, approximately 10% of the patches going into the mainline
|
||||||
|
get there via -mm.
|
||||||
|
|
||||||
|
The current -mm patch can always be found from the front page of
|
||||||
|
|
||||||
|
http://kernel.org/
|
||||||
|
|
||||||
|
Those who want to see the current state of -mm can get the "-mm of the
|
||||||
|
moment" tree, found at:
|
||||||
|
|
||||||
|
http://userweb.kernel.org/~akpm/mmotm/
|
||||||
|
|
||||||
|
Use of the MMOTM tree is likely to be a frustrating experience, though;
|
||||||
|
there is a definite chance that it will not even compile.
|
||||||
|
|
||||||
|
The other staging tree, started more recently, is linux-next, maintained by
|
||||||
|
Stephen Rothwell. The linux-next tree is, by design, a snapshot of what
|
||||||
|
the mainline is expected to look like after the next merge window closes.
|
||||||
|
Linux-next trees are announced on the linux-kernel and linux-next mailing
|
||||||
|
lists when they are assembled; they can be downloaded from:
|
||||||
|
|
||||||
|
http://www.kernel.org/pub/linux/kernel/people/sfr/linux-next/
|
||||||
|
|
||||||
|
Some information about linux-next has been gathered at:
|
||||||
|
|
||||||
|
http://linux.f-seidel.de/linux-next/pmwiki/
|
||||||
|
|
||||||
|
How the linux-next tree will fit into the development process is still
|
||||||
|
changing. As of this writing, the first full development cycle involving
|
||||||
|
linux-next (2.6.26) is coming to an end; thus far, it has proved to be a
|
||||||
|
valuable resource for finding and fixing integration problems before the
|
||||||
|
beginning of the merge window. See http://lwn.net/Articles/287155/ for
|
||||||
|
more information on how linux-next has worked to set up the 2.6.27 merge
|
||||||
|
window.
|
||||||
|
|
||||||
|
Some developers have begun to suggest that linux-next should be used as the
|
||||||
|
target for future development as well. The linux-next tree does tend to be
|
||||||
|
far ahead of the mainline and is more representative of the tree into which
|
||||||
|
any new work will be merged. The downside to this idea is that the
|
||||||
|
volatility of linux-next tends to make it a difficult development target.
|
||||||
|
See http://lwn.net/Articles/289013/ for more information on this topic, and
|
||||||
|
stay tuned; much is still in flux where linux-next is involved.
|
||||||
|
|
||||||
|
|
||||||
|
2.5: TOOLS
|
||||||
|
|
||||||
|
As can be seen from the above text, the kernel development process depends
|
||||||
|
heavily on the ability to herd collections of patches in various
|
||||||
|
directions. The whole thing would not work anywhere near as well as it
|
||||||
|
does without suitably powerful tools. Tutorials on how to use these tools
|
||||||
|
are well beyond the scope of this document, but there is space for a few
|
||||||
|
pointers.
|
||||||
|
|
||||||
|
By far the dominant source code management system used by the kernel
|
||||||
|
community is git. Git is one of a number of distributed version control
|
||||||
|
systems being developed in the free software community. It is well tuned
|
||||||
|
for kernel development, in that it performs quite well when dealing with
|
||||||
|
large repositories and large numbers of patches. It also has a reputation
|
||||||
|
for being difficult to learn and use, though it has gotten better over
|
||||||
|
time. Some sort of familiarity with git is almost a requirement for kernel
|
||||||
|
developers; even if they do not use it for their own work, they'll need git
|
||||||
|
to keep up with what other developers (and the mainline) are doing.
|
||||||
|
|
||||||
|
Git is now packaged by almost all Linux distributions. There is a home
|
||||||
|
page at
|
||||||
|
|
||||||
|
http://git.or.cz/
|
||||||
|
|
||||||
|
That page has pointers to documentation and tutorials. One should be
|
||||||
|
aware, in particular, of the Kernel Hacker's Guide to git, which has
|
||||||
|
information specific to kernel development:
|
||||||
|
|
||||||
|
http://linux.yyz.us/git-howto.html
|
||||||
|
|
||||||
|
Among the kernel developers who do not use git, the most popular choice is
|
||||||
|
almost certainly Mercurial:
|
||||||
|
|
||||||
|
http://www.selenic.com/mercurial/
|
||||||
|
|
||||||
|
Mercurial shares many features with git, but it provides an interface which
|
||||||
|
many find easier to use.
|
||||||
|
|
||||||
|
The other tool worth knowing about is Quilt:
|
||||||
|
|
||||||
|
http://savannah.nongnu.org/projects/quilt/
|
||||||
|
|
||||||
|
Quilt is a patch management system, rather than a source code management
|
||||||
|
system. It does not track history over time; it is, instead, oriented
|
||||||
|
toward tracking a specific set of changes against an evolving code base.
|
||||||
|
Some major subsystem maintainers use quilt to manage patches intended to go
|
||||||
|
upstream. For the management of certain kinds of trees (-mm, for example),
|
||||||
|
quilt is the best tool for the job.
|
||||||
|
|
||||||
|
|
||||||
|
2.6: MAILING LISTS
|
||||||
|
|
||||||
|
A great deal of Linux kernel development work is done by way of mailing
|
||||||
|
lists. It is hard to be a fully-functioning member of the community
|
||||||
|
without joining at least one list somewhere. But Linux mailing lists also
|
||||||
|
represent a potential hazard to developers, who risk getting buried under a
|
||||||
|
load of electronic mail, running afoul of the conventions used on the Linux
|
||||||
|
lists, or both.
|
||||||
|
|
||||||
|
Most kernel mailing lists are run on vger.kernel.org; the master list can
|
||||||
|
be found at:
|
||||||
|
|
||||||
|
http://vger.kernel.org/vger-lists.html
|
||||||
|
|
||||||
|
There are lists hosted elsewhere, though; a number of them are at
|
||||||
|
lists.redhat.com.
|
||||||
|
|
||||||
|
The core mailing list for kernel development is, of course, linux-kernel.
|
||||||
|
This list is an intimidating place to be; volume can reach 500 messages per
|
||||||
|
day, the amount of noise is high, the conversation can be severely
|
||||||
|
technical, and participants are not always concerned with showing a high
|
||||||
|
degree of politeness. But there is no other place where the kernel
|
||||||
|
development community comes together as a whole; developers who avoid this
|
||||||
|
list will miss important information.
|
||||||
|
|
||||||
|
There are a few hints which can help with linux-kernel survival:
|
||||||
|
|
||||||
|
- Have the list delivered to a separate folder, rather than your main
|
||||||
|
mailbox. One must be able to ignore the stream for sustained periods of
|
||||||
|
time.
|
||||||
|
|
||||||
|
- Do not try to follow every conversation - nobody else does. It is
|
||||||
|
important to filter on both the topic of interest (though note that
|
||||||
|
long-running conversations can drift away from the original subject
|
||||||
|
without changing the email subject line) and the people who are
|
||||||
|
participating.
|
||||||
|
|
||||||
|
- Do not feed the trolls. If somebody is trying to stir up an angry
|
||||||
|
response, ignore them.
|
||||||
|
|
||||||
|
- When responding to linux-kernel email (or that on other lists) preserve
|
||||||
|
the Cc: header for all involved. In the absence of a strong reason (such
|
||||||
|
as an explicit request), you should never remove recipients. Always make
|
||||||
|
sure that the person you are responding to is in the Cc: list. This
|
||||||
|
convention also makes it unnecessary to explicitly ask to be copied on
|
||||||
|
replies to your postings.
|
||||||
|
|
||||||
|
- Search the list archives (and the net as a whole) before asking
|
||||||
|
questions. Some developers can get impatient with people who clearly
|
||||||
|
have not done their homework.
|
||||||
|
|
||||||
|
- Avoid top-posting (the practice of putting your answer above the quoted
|
||||||
|
text you are responding to). It makes your response harder to read and
|
||||||
|
makes a poor impression.
|
||||||
|
|
||||||
|
- Ask on the correct mailing list. Linux-kernel may be the general meeting
|
||||||
|
point, but it is not the best place to find developers from all
|
||||||
|
subsystems.
|
||||||
|
|
||||||
|
The last point - finding the correct mailing list - is a common place for
|
||||||
|
beginning developers to go wrong. Somebody who asks a networking-related
|
||||||
|
question on linux-kernel will almost certainly receive a polite suggestion
|
||||||
|
to ask on the netdev list instead, as that is the list frequented by most
|
||||||
|
networking developers. Other lists exist for the SCSI, video4linux, IDE,
|
||||||
|
filesystem, etc. subsystems. The best place to look for mailing lists is
|
||||||
|
in the MAINTAINERS file packaged with the kernel source.
|
||||||
|
|
||||||
|
|
||||||
|
2.7: GETTING STARTED WITH KERNEL DEVELOPMENT
|
||||||
|
|
||||||
|
Questions about how to get started with the kernel development process are
|
||||||
|
common - from both individuals and companies. Equally common are missteps
|
||||||
|
which make the beginning of the relationship harder than it has to be.
|
||||||
|
|
||||||
|
Companies often look to hire well-known developers to get a development
|
||||||
|
group started. This can, in fact, be an effective technique. But it also
|
||||||
|
tends to be expensive and does not do much to grow the pool of experienced
|
||||||
|
kernel developers. It is possible to bring in-house developers up to speed
|
||||||
|
on Linux kernel development, given the investment of a bit of time. Taking
|
||||||
|
this time can endow an employer with a group of developers who understand
|
||||||
|
the kernel and the company both, and who can help to train others as well.
|
||||||
|
Over the medium term, this is often the more profitable approach.
|
||||||
|
|
||||||
|
Individual developers are often, understandably, at a loss for a place to
|
||||||
|
start. Beginning with a large project can be intimidating; one often wants
|
||||||
|
to test the waters with something smaller first. This is the point where
|
||||||
|
some developers jump into the creation of patches fixing spelling errors or
|
||||||
|
minor coding style issues. Unfortunately, such patches create a level of
|
||||||
|
noise which is distracting for the development community as a whole, so,
|
||||||
|
increasingly, they are looked down upon. New developers wishing to
|
||||||
|
introduce themselves to the community will not get the sort of reception
|
||||||
|
they wish for by these means.
|
||||||
|
|
||||||
|
Andrew Morton gives this advice for aspiring kernel developers
|
||||||
|
|
||||||
|
The #1 project for all kernel beginners should surely be "make sure
|
||||||
|
that the kernel runs perfectly at all times on all machines which
|
||||||
|
you can lay your hands on". Usually the way to do this is to work
|
||||||
|
with others on getting things fixed up (this can require
|
||||||
|
persistence!) but that's fine - it's a part of kernel development.
|
||||||
|
|
||||||
|
(http://lwn.net/Articles/283982/).
|
||||||
|
|
||||||
|
In the absence of obvious problems to fix, developers are advised to look
|
||||||
|
at the current lists of regressions and open bugs in general. There is
|
||||||
|
never any shortage of issues in need of fixing; by addressing these issues,
|
||||||
|
developers will gain experience with the process while, at the same time,
|
||||||
|
building respect with the rest of the development community.
|
|
@ -0,0 +1,195 @@
|
||||||
|
3: EARLY-STAGE PLANNING
|
||||||
|
|
||||||
|
When contemplating a Linux kernel development project, it can be tempting
|
||||||
|
to jump right in and start coding. As with any significant project,
|
||||||
|
though, much of the groundwork for success is best laid before the first
|
||||||
|
line of code is written. Some time spent in early planning and
|
||||||
|
communication can save far more time later on.
|
||||||
|
|
||||||
|
|
||||||
|
3.1: SPECIFYING THE PROBLEM
|
||||||
|
|
||||||
|
Like any engineering project, a successful kernel enhancement starts with a
|
||||||
|
clear description of the problem to be solved. In some cases, this step is
|
||||||
|
easy: when a driver is needed for a specific piece of hardware, for
|
||||||
|
example. In others, though, it is tempting to confuse the real problem
|
||||||
|
with the proposed solution, and that can lead to difficulties.
|
||||||
|
|
||||||
|
Consider an example: some years ago, developers working with Linux audio
|
||||||
|
sought a way to run applications without dropouts or other artifacts caused
|
||||||
|
by excessive latency in the system. The solution they arrived at was a
|
||||||
|
kernel module intended to hook into the Linux Security Module (LSM)
|
||||||
|
framework; this module could be configured to give specific applications
|
||||||
|
access to the realtime scheduler. This module was implemented and sent to
|
||||||
|
the linux-kernel mailing list, where it immediately ran into problems.
|
||||||
|
|
||||||
|
To the audio developers, this security module was sufficient to solve their
|
||||||
|
immediate problem. To the wider kernel community, though, it was seen as a
|
||||||
|
misuse of the LSM framework (which is not intended to confer privileges
|
||||||
|
onto processes which they would not otherwise have) and a risk to system
|
||||||
|
stability. Their preferred solutions involved realtime scheduling access
|
||||||
|
via the rlimit mechanism for the short term, and ongoing latency reduction
|
||||||
|
work in the long term.
|
||||||
|
|
||||||
|
The audio community, however, could not see past the particular solution
|
||||||
|
they had implemented; they were unwilling to accept alternatives. The
|
||||||
|
resulting disagreement left those developers feeling disillusioned with the
|
||||||
|
entire kernel development process; one of them went back to an audio list
|
||||||
|
and posted this:
|
||||||
|
|
||||||
|
There are a number of very good Linux kernel developers, but they
|
||||||
|
tend to get outshouted by a large crowd of arrogant fools. Trying
|
||||||
|
to communicate user requirements to these people is a waste of
|
||||||
|
time. They are much too "intelligent" to listen to lesser mortals.
|
||||||
|
|
||||||
|
(http://lwn.net/Articles/131776/).
|
||||||
|
|
||||||
|
The reality of the situation was different; the kernel developers were far
|
||||||
|
more concerned about system stability, long-term maintenance, and finding
|
||||||
|
the right solution to the problem than they were with a specific module.
|
||||||
|
The moral of the story is to focus on the problem - not a specific solution
|
||||||
|
- and to discuss it with the development community before investing in the
|
||||||
|
creation of a body of code.
|
||||||
|
|
||||||
|
So, when contemplating a kernel development project, one should obtain
|
||||||
|
answers to a short set of questions:
|
||||||
|
|
||||||
|
- What, exactly, is the problem which needs to be solved?
|
||||||
|
|
||||||
|
- Who are the users affected by this problem? Which use cases should the
|
||||||
|
solution address?
|
||||||
|
|
||||||
|
- How does the kernel fall short in addressing that problem now?
|
||||||
|
|
||||||
|
Only then does it make sense to start considering possible solutions.
|
||||||
|
|
||||||
|
|
||||||
|
3.2: EARLY DISCUSSION
|
||||||
|
|
||||||
|
When planning a kernel development project, it makes great sense to hold
|
||||||
|
discussions with the community before launching into implementation. Early
|
||||||
|
communication can save time and trouble in a number of ways:
|
||||||
|
|
||||||
|
- It may well be that the problem is addressed by the kernel in ways which
|
||||||
|
you have not understood. The Linux kernel is large and has a number of
|
||||||
|
features and capabilities which are not immediately obvious. Not all
|
||||||
|
kernel capabilities are documented as well as one might like, and it is
|
||||||
|
easy to miss things. Your author has seen the posting of a complete
|
||||||
|
driver which duplicated an existing driver that the new author had been
|
||||||
|
unaware of. Code which reinvents existing wheels is not only wasteful;
|
||||||
|
it will also not be accepted into the mainline kernel.
|
||||||
|
|
||||||
|
- There may be elements of the proposed solution which will not be
|
||||||
|
acceptable for mainline merging. It is better to find out about
|
||||||
|
problems like this before writing the code.
|
||||||
|
|
||||||
|
- It's entirely possible that other developers have thought about the
|
||||||
|
problem; they may have ideas for a better solution, and may be willing
|
||||||
|
to help in the creation of that solution.
|
||||||
|
|
||||||
|
Years of experience with the kernel development community have taught a
|
||||||
|
clear lesson: kernel code which is designed and developed behind closed
|
||||||
|
doors invariably has problems which are only revealed when the code is
|
||||||
|
released into the community. Sometimes these problems are severe,
|
||||||
|
requiring months or years of effort before the code can be brought up to
|
||||||
|
the kernel community's standards. Some examples include:
|
||||||
|
|
||||||
|
- The Devicescape network stack was designed and implemented for
|
||||||
|
single-processor systems. It could not be merged into the mainline
|
||||||
|
until it was made suitable for multiprocessor systems. Retrofitting
|
||||||
|
locking and such into code is a difficult task; as a result, the merging
|
||||||
|
of this code (now called mac80211) was delayed for over a year.
|
||||||
|
|
||||||
|
- The Reiser4 filesystem included a number of capabilities which, in the
|
||||||
|
core kernel developers' opinion, should have been implemented in the
|
||||||
|
virtual filesystem layer instead. It also included features which could
|
||||||
|
not easily be implemented without exposing the system to user-caused
|
||||||
|
deadlocks. The late revelation of these problems - and refusal to
|
||||||
|
address some of them - has caused Reiser4 to stay out of the mainline
|
||||||
|
kernel.
|
||||||
|
|
||||||
|
- The AppArmor security module made use of internal virtual filesystem
|
||||||
|
data structures in ways which were considered to be unsafe and
|
||||||
|
unreliable. This code has since been significantly reworked, but
|
||||||
|
remains outside of the mainline.
|
||||||
|
|
||||||
|
In each of these cases, a great deal of pain and extra work could have been
|
||||||
|
avoided with some early discussion with the kernel developers.
|
||||||
|
|
||||||
|
|
||||||
|
3.3: WHO DO YOU TALK TO?
|
||||||
|
|
||||||
|
When developers decide to take their plans public, the next question will
|
||||||
|
be: where do we start? The answer is to find the right mailing list(s) and
|
||||||
|
the right maintainer. For mailing lists, the best approach is to look in
|
||||||
|
the MAINTAINERS file for a relevant place to post. If there is a suitable
|
||||||
|
subsystem list, posting there is often preferable to posting on
|
||||||
|
linux-kernel; you are more likely to reach developers with expertise in the
|
||||||
|
relevant subsystem and the environment may be more supportive.
|
||||||
|
|
||||||
|
Finding maintainers can be a bit harder. Again, the MAINTAINERS file is
|
||||||
|
the place to start. That file tends to not always be up to date, though,
|
||||||
|
and not all subsystems are represented there. The person listed in the
|
||||||
|
MAINTAINERS file may, in fact, not be the person who is actually acting in
|
||||||
|
that role currently. So, when there is doubt about who to contact, a
|
||||||
|
useful trick is to use git (and "git log" in particular) to see who is
|
||||||
|
currently active within the subsystem of interest. Look at who is writing
|
||||||
|
patches, and who, if anybody, is attaching Signed-off-by lines to those
|
||||||
|
patches. Those are the people who will be best placed to help with a new
|
||||||
|
development project.
|
||||||
|
|
||||||
|
If all else fails, talking to Andrew Morton can be an effective way to
|
||||||
|
track down a maintainer for a specific piece of code.
|
||||||
|
|
||||||
|
|
||||||
|
3.4: WHEN TO POST?
|
||||||
|
|
||||||
|
If possible, posting your plans during the early stages can only be
|
||||||
|
helpful. Describe the problem being solved and any plans that have been
|
||||||
|
made on how the implementation will be done. Any information you can
|
||||||
|
provide can help the development community provide useful input on the
|
||||||
|
project.
|
||||||
|
|
||||||
|
One discouraging thing which can happen at this stage is not a hostile
|
||||||
|
reaction, but, instead, little or no reaction at all. The sad truth of the
|
||||||
|
matter is (1) kernel developers tend to be busy, (2) there is no shortage
|
||||||
|
of people with grand plans and little code (or even prospect of code) to
|
||||||
|
back them up, and (3) nobody is obligated to review or comment on ideas
|
||||||
|
posted by others. If a request-for-comments posting yields little in the
|
||||||
|
way of comments, do not assume that it means there is no interest in the
|
||||||
|
project. Unfortunately, you also cannot assume that there are no problems
|
||||||
|
with your idea. The best thing to do in this situation is to proceed,
|
||||||
|
keeping the community informed as you go.
|
||||||
|
|
||||||
|
|
||||||
|
3.5: GETTING OFFICIAL BUY-IN
|
||||||
|
|
||||||
|
If your work is being done in a corporate environment - as most Linux
|
||||||
|
kernel work is - you must, obviously, have permission from suitably
|
||||||
|
empowered managers before you can post your company's plans or code to a
|
||||||
|
public mailing list. The posting of code which has not been cleared for
|
||||||
|
release under a GPL-compatible license can be especially problematic; the
|
||||||
|
sooner that a company's management and legal staff can agree on the posting
|
||||||
|
of a kernel development project, the better off everybody involved will be.
|
||||||
|
|
||||||
|
Some readers may be thinking at this point that their kernel work is
|
||||||
|
intended to support a product which does not yet have an officially
|
||||||
|
acknowledged existence. Revealing their employer's plans on a public
|
||||||
|
mailing list may not be a viable option. In cases like this, it is worth
|
||||||
|
considering whether the secrecy is really necessary; there is often no real
|
||||||
|
need to keep development plans behind closed doors.
|
||||||
|
|
||||||
|
That said, there are also cases where a company legitimately cannot
|
||||||
|
disclose its plans early in the development process. Companies with
|
||||||
|
experienced kernel developers may choose to proceed in an open-loop manner
|
||||||
|
on the assumption that they will be able to avoid serious integration
|
||||||
|
problems later. For companies without that sort of in-house expertise, the
|
||||||
|
best option is often to hire an outside developer to review the plans under
|
||||||
|
a non-disclosure agreement. The Linux Foundation operates an NDA program
|
||||||
|
designed to help with this sort of situation; more information can be found
|
||||||
|
at:
|
||||||
|
|
||||||
|
http://www.linuxfoundation.org/en/NDA_program
|
||||||
|
|
||||||
|
This kind of review is often enough to avoid serious problems later on
|
||||||
|
without requiring public disclosure of the project.
|
|
@ -0,0 +1,384 @@
|
||||||
|
4: GETTING THE CODE RIGHT
|
||||||
|
|
||||||
|
While there is much to be said for a solid and community-oriented design
|
||||||
|
process, the proof of any kernel development project is in the resulting
|
||||||
|
code. It is the code which will be examined by other developers and merged
|
||||||
|
(or not) into the mainline tree. So it is the quality of this code which
|
||||||
|
will determine the ultimate success of the project.
|
||||||
|
|
||||||
|
This section will examine the coding process. We'll start with a look at a
|
||||||
|
number of ways in which kernel developers can go wrong. Then the focus
|
||||||
|
will shift toward doing things right and the tools which can help in that
|
||||||
|
quest.
|
||||||
|
|
||||||
|
|
||||||
|
4.1: PITFALLS
|
||||||
|
|
||||||
|
* Coding style
|
||||||
|
|
||||||
|
The kernel has long had a standard coding style, described in
|
||||||
|
Documentation/CodingStyle. For much of that time, the policies described
|
||||||
|
in that file were taken as being, at most, advisory. As a result, there is
|
||||||
|
a substantial amount of code in the kernel which does not meet the coding
|
||||||
|
style guidelines. The presence of that code leads to two independent
|
||||||
|
hazards for kernel developers.
|
||||||
|
|
||||||
|
The first of these is to believe that the kernel coding standards do not
|
||||||
|
matter and are not enforced. The truth of the matter is that adding new
|
||||||
|
code to the kernel is very difficult if that code is not coded according to
|
||||||
|
the standard; many developers will request that the code be reformatted
|
||||||
|
before they will even review it. A code base as large as the kernel
|
||||||
|
requires some uniformity of code to make it possible for developers to
|
||||||
|
quickly understand any part of it. So there is no longer room for
|
||||||
|
strangely-formatted code.
|
||||||
|
|
||||||
|
Occasionally, the kernel's coding style will run into conflict with an
|
||||||
|
employer's mandated style. In such cases, the kernel's style will have to
|
||||||
|
win before the code can be merged. Putting code into the kernel means
|
||||||
|
giving up a degree of control in a number of ways - including control over
|
||||||
|
how the code is formatted.
|
||||||
|
|
||||||
|
The other trap is to assume that code which is already in the kernel is
|
||||||
|
urgently in need of coding style fixes. Developers may start to generate
|
||||||
|
reformatting patches as a way of gaining familiarity with the process, or
|
||||||
|
as a way of getting their name into the kernel changelogs - or both. But
|
||||||
|
pure coding style fixes are seen as noise by the development community;
|
||||||
|
they tend to get a chilly reception. So this type of patch is best
|
||||||
|
avoided. It is natural to fix the style of a piece of code while working
|
||||||
|
on it for other reasons, but coding style changes should not be made for
|
||||||
|
their own sake.
|
||||||
|
|
||||||
|
The coding style document also should not be read as an absolute law which
|
||||||
|
can never be transgressed. If there is a good reason to go against the
|
||||||
|
style (a line which becomes far less readable if split to fit within the
|
||||||
|
80-column limit, for example), just do it.
|
||||||
|
|
||||||
|
|
||||||
|
* Abstraction layers
|
||||||
|
|
||||||
|
Computer Science professors teach students to make extensive use of
|
||||||
|
abstraction layers in the name of flexibility and information hiding.
|
||||||
|
Certainly the kernel makes extensive use of abstraction; no project
|
||||||
|
involving several million lines of code could do otherwise and survive.
|
||||||
|
But experience has shown that excessive or premature abstraction can be
|
||||||
|
just as harmful as premature optimization. Abstraction should be used to
|
||||||
|
the level required and no further.
|
||||||
|
|
||||||
|
At a simple level, consider a function which has an argument which is
|
||||||
|
always passed as zero by all callers. One could retain that argument just
|
||||||
|
in case somebody eventually needs to use the extra flexibility that it
|
||||||
|
provides. By that time, though, chances are good that the code which
|
||||||
|
implements this extra argument has been broken in some subtle way which was
|
||||||
|
never noticed - because it has never been used. Or, when the need for
|
||||||
|
extra flexibility arises, it does not do so in a way which matches the
|
||||||
|
programmer's early expectation. Kernel developers will routinely submit
|
||||||
|
patches to remove unused arguments; they should, in general, not be added
|
||||||
|
in the first place.
|
||||||
|
|
||||||
|
Abstraction layers which hide access to hardware - often to allow the bulk
|
||||||
|
of a driver to be used with multiple operating systems - are especially
|
||||||
|
frowned upon. Such layers obscure the code and may impose a performance
|
||||||
|
penalty; they do not belong in the Linux kernel.
|
||||||
|
|
||||||
|
On the other hand, if you find yourself copying significant amounts of code
|
||||||
|
from another kernel subsystem, it is time to ask whether it would, in fact,
|
||||||
|
make sense to pull out some of that code into a separate library or to
|
||||||
|
implement that functionality at a higher level. There is no value in
|
||||||
|
replicating the same code throughout the kernel.
|
||||||
|
|
||||||
|
|
||||||
|
* #ifdef and preprocessor use in general
|
||||||
|
|
||||||
|
The C preprocessor seems to present a powerful temptation to some C
|
||||||
|
programmers, who see it as a way to efficiently encode a great deal of
|
||||||
|
flexibility into a source file. But the preprocessor is not C, and heavy
|
||||||
|
use of it results in code which is much harder for others to read and
|
||||||
|
harder for the compiler to check for correctness. Heavy preprocessor use
|
||||||
|
is almost always a sign of code which needs some cleanup work.
|
||||||
|
|
||||||
|
Conditional compilation with #ifdef is, indeed, a powerful feature, and it
|
||||||
|
is used within the kernel. But there is little desire to see code which is
|
||||||
|
sprinkled liberally with #ifdef blocks. As a general rule, #ifdef use
|
||||||
|
should be confined to header files whenever possible.
|
||||||
|
Conditionally-compiled code can be confined to functions which, if the code
|
||||||
|
is not to be present, simply become empty. The compiler will then quietly
|
||||||
|
optimize out the call to the empty function. The result is far cleaner
|
||||||
|
code which is easier to follow.
|
||||||
|
|
||||||
|
C preprocessor macros present a number of hazards, including possible
|
||||||
|
multiple evaluation of expressions with side effects and no type safety.
|
||||||
|
If you are tempted to define a macro, consider creating an inline function
|
||||||
|
instead. The code which results will be the same, but inline functions are
|
||||||
|
easier to read, do not evaluate their arguments multiple times, and allow
|
||||||
|
the compiler to perform type checking on the arguments and return value.
|
||||||
|
|
||||||
|
|
||||||
|
* Inline functions
|
||||||
|
|
||||||
|
Inline functions present a hazard of their own, though. Programmers can
|
||||||
|
become enamored of the perceived efficiency inherent in avoiding a function
|
||||||
|
call and fill a source file with inline functions. Those functions,
|
||||||
|
however, can actually reduce performance. Since their code is replicated
|
||||||
|
at each call site, they end up bloating the size of the compiled kernel.
|
||||||
|
That, in turn, creates pressure on the processor's memory caches, which can
|
||||||
|
slow execution dramatically. Inline functions, as a rule, should be quite
|
||||||
|
small and relatively rare. The cost of a function call, after all, is not
|
||||||
|
that high; the creation of large numbers of inline functions is a classic
|
||||||
|
example of premature optimization.
|
||||||
|
|
||||||
|
In general, kernel programmers ignore cache effects at their peril. The
|
||||||
|
classic time/space tradeoff taught in beginning data structures classes
|
||||||
|
often does not apply to contemporary hardware. Space *is* time, in that a
|
||||||
|
larger program will run slower than one which is more compact.
|
||||||
|
|
||||||
|
|
||||||
|
* Locking
|
||||||
|
|
||||||
|
In May, 2006, the "Devicescape" networking stack was, with great
|
||||||
|
fanfare, released under the GPL and made available for inclusion in the
|
||||||
|
mainline kernel. This donation was welcome news; support for wireless
|
||||||
|
networking in Linux was considered substandard at best, and the Devicescape
|
||||||
|
stack offered the promise of fixing that situation. Yet, this code did not
|
||||||
|
actually make it into the mainline until June, 2007 (2.6.22). What
|
||||||
|
happened?
|
||||||
|
|
||||||
|
This code showed a number of signs of having been developed behind
|
||||||
|
corporate doors. But one large problem in particular was that it was not
|
||||||
|
designed to work on multiprocessor systems. Before this networking stack
|
||||||
|
(now called mac80211) could be merged, a locking scheme needed to be
|
||||||
|
retrofitted onto it.
|
||||||
|
|
||||||
|
Once upon a time, Linux kernel code could be developed without thinking
|
||||||
|
about the concurrency issues presented by multiprocessor systems. Now,
|
||||||
|
however, this document is being written on a dual-core laptop. Even on
|
||||||
|
single-processor systems, work being done to improve responsiveness will
|
||||||
|
raise the level of concurrency within the kernel. The days when kernel
|
||||||
|
code could be written without thinking about locking are long past.
|
||||||
|
|
||||||
|
Any resource (data structures, hardware registers, etc.) which could be
|
||||||
|
accessed concurrently by more than one thread must be protected by a lock.
|
||||||
|
New code should be written with this requirement in mind; retrofitting
|
||||||
|
locking after the fact is a rather more difficult task. Kernel developers
|
||||||
|
should take the time to understand the available locking primitives well
|
||||||
|
enough to pick the right tool for the job. Code which shows a lack of
|
||||||
|
attention to concurrency will have a difficult path into the mainline.
|
||||||
|
|
||||||
|
|
||||||
|
* Regressions
|
||||||
|
|
||||||
|
One final hazard worth mentioning is this: it can be tempting to make a
|
||||||
|
change (which may bring big improvements) which causes something to break
|
||||||
|
for existing users. This kind of change is called a "regression," and
|
||||||
|
regressions have become most unwelcome in the mainline kernel. With few
|
||||||
|
exceptions, changes which cause regressions will be backed out if the
|
||||||
|
regression cannot be fixed in a timely manner. Far better to avoid the
|
||||||
|
regression in the first place.
|
||||||
|
|
||||||
|
It is often argued that a regression can be justified if it causes things
|
||||||
|
to work for more people than it creates problems for. Why not make a
|
||||||
|
change if it brings new functionality to ten systems for each one it
|
||||||
|
breaks? The best answer to this question was expressed by Linus in July,
|
||||||
|
2007:
|
||||||
|
|
||||||
|
So we don't fix bugs by introducing new problems. That way lies
|
||||||
|
madness, and nobody ever knows if you actually make any real
|
||||||
|
progress at all. Is it two steps forwards, one step back, or one
|
||||||
|
step forward and two steps back?
|
||||||
|
|
||||||
|
(http://lwn.net/Articles/243460/).
|
||||||
|
|
||||||
|
An especially unwelcome type of regression is any sort of change to the
|
||||||
|
user-space ABI. Once an interface has been exported to user space, it must
|
||||||
|
be supported indefinitely. This fact makes the creation of user-space
|
||||||
|
interfaces particularly challenging: since they cannot be changed in
|
||||||
|
incompatible ways, they must be done right the first time. For this
|
||||||
|
reason, a great deal of thought, clear documentation, and wide review for
|
||||||
|
user-space interfaces is always required.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
4.2: CODE CHECKING TOOLS
|
||||||
|
|
||||||
|
For now, at least, the writing of error-free code remains an ideal that few
|
||||||
|
of us can reach. What we can hope to do, though, is to catch and fix as
|
||||||
|
many of those errors as possible before our code goes into the mainline
|
||||||
|
kernel. To that end, the kernel developers have put together an impressive
|
||||||
|
array of tools which can catch a wide variety of obscure problems in an
|
||||||
|
automated way. Any problem caught by the computer is a problem which will
|
||||||
|
not afflict a user later on, so it stands to reason that the automated
|
||||||
|
tools should be used whenever possible.
|
||||||
|
|
||||||
|
The first step is simply to heed the warnings produced by the compiler.
|
||||||
|
Contemporary versions of gcc can detect (and warn about) a large number of
|
||||||
|
potential errors. Quite often, these warnings point to real problems.
|
||||||
|
Code submitted for review should, as a rule, not produce any compiler
|
||||||
|
warnings. When silencing warnings, take care to understand the real cause
|
||||||
|
and try to avoid "fixes" which make the warning go away without addressing
|
||||||
|
its cause.
|
||||||
|
|
||||||
|
Note that not all compiler warnings are enabled by default. Build the
|
||||||
|
kernel with "make EXTRA_CFLAGS=-W" to get the full set.
|
||||||
|
|
||||||
|
The kernel provides several configuration options which turn on debugging
|
||||||
|
features; most of these are found in the "kernel hacking" submenu. Several
|
||||||
|
of these options should be turned on for any kernel used for development or
|
||||||
|
testing purposes. In particular, you should turn on:
|
||||||
|
|
||||||
|
- ENABLE_WARN_DEPRECATED, ENABLE_MUST_CHECK, and FRAME_WARN to get an
|
||||||
|
extra set of warnings for problems like the use of deprecated interfaces
|
||||||
|
or ignoring an important return value from a function. The output
|
||||||
|
generated by these warnings can be verbose, but one need not worry about
|
||||||
|
warnings from other parts of the kernel.
|
||||||
|
|
||||||
|
- DEBUG_OBJECTS will add code to track the lifetime of various objects
|
||||||
|
created by the kernel and warn when things are done out of order. If
|
||||||
|
you are adding a subsystem which creates (and exports) complex objects
|
||||||
|
of its own, consider adding support for the object debugging
|
||||||
|
infrastructure.
|
||||||
|
|
||||||
|
- DEBUG_SLAB can find a variety of memory allocation and use errors; it
|
||||||
|
should be used on most development kernels.
|
||||||
|
|
||||||
|
- DEBUG_SPINLOCK, DEBUG_SPINLOCK_SLEEP, and DEBUG_MUTEXES will find a
|
||||||
|
number of common locking errors.
|
||||||
|
|
||||||
|
There are quite a few other debugging options, some of which will be
|
||||||
|
discussed below. Some of them have a significant performance impact and
|
||||||
|
should not be used all of the time. But some time spent learning the
|
||||||
|
available options will likely be paid back many times over in short order.
|
||||||
|
|
||||||
|
One of the heavier debugging tools is the locking checker, or "lockdep."
|
||||||
|
This tool will track the acquisition and release of every lock (spinlock or
|
||||||
|
mutex) in the system, the order in which locks are acquired relative to
|
||||||
|
each other, the current interrupt environment, and more. It can then
|
||||||
|
ensure that locks are always acquired in the same order, that the same
|
||||||
|
interrupt assumptions apply in all situations, and so on. In other words,
|
||||||
|
lockdep can find a number of scenarios in which the system could, on rare
|
||||||
|
occasion, deadlock. This kind of problem can be painful (for both
|
||||||
|
developers and users) in a deployed system; lockdep allows them to be found
|
||||||
|
in an automated manner ahead of time. Code with any sort of non-trivial
|
||||||
|
locking should be run with lockdep enabled before being submitted for
|
||||||
|
inclusion.
|
||||||
|
|
||||||
|
As a diligent kernel programmer, you will, beyond doubt, check the return
|
||||||
|
status of any operation (such as a memory allocation) which can fail. The
|
||||||
|
fact of the matter, though, is that the resulting failure recovery paths
|
||||||
|
are, probably, completely untested. Untested code tends to be broken code;
|
||||||
|
you could be much more confident of your code if all those error-handling
|
||||||
|
paths had been exercised a few times.
|
||||||
|
|
||||||
|
The kernel provides a fault injection framework which can do exactly that,
|
||||||
|
especially where memory allocations are involved. With fault injection
|
||||||
|
enabled, a configurable percentage of memory allocations will be made to
|
||||||
|
fail; these failures can be restricted to a specific range of code.
|
||||||
|
Running with fault injection enabled allows the programmer to see how the
|
||||||
|
code responds when things go badly. See
|
||||||
|
Documentation/fault-injection/fault-injection.text for more information on
|
||||||
|
how to use this facility.
|
||||||
|
|
||||||
|
Other kinds of errors can be found with the "sparse" static analysis tool.
|
||||||
|
With sparse, the programmer can be warned about confusion between
|
||||||
|
user-space and kernel-space addresses, mixture of big-endian and
|
||||||
|
small-endian quantities, the passing of integer values where a set of bit
|
||||||
|
flags is expected, and so on. Sparse must be installed separately (it can
|
||||||
|
be found at http://www.kernel.org/pub/software/devel/sparse/ if your
|
||||||
|
distributor does not package it); it can then be run on the code by adding
|
||||||
|
"C=1" to your make command.
|
||||||
|
|
||||||
|
Other kinds of portability errors are best found by compiling your code for
|
||||||
|
other architectures. If you do not happen to have an S/390 system or a
|
||||||
|
Blackfin development board handy, you can still perform the compilation
|
||||||
|
step. A large set of cross compilers for x86 systems can be found at
|
||||||
|
|
||||||
|
http://www.kernel.org/pub/tools/crosstool/
|
||||||
|
|
||||||
|
Some time spent installing and using these compilers will help avoid
|
||||||
|
embarrassment later.
|
||||||
|
|
||||||
|
|
||||||
|
4.3: DOCUMENTATION
|
||||||
|
|
||||||
|
Documentation has often been more the exception than the rule with kernel
|
||||||
|
development. Even so, adequate documentation will help to ease the merging
|
||||||
|
of new code into the kernel, make life easier for other developers, and
|
||||||
|
will be helpful for your users. In many cases, the addition of
|
||||||
|
documentation has become essentially mandatory.
|
||||||
|
|
||||||
|
The first piece of documentation for any patch is its associated
|
||||||
|
changelog. Log entries should describe the problem being solved, the form
|
||||||
|
of the solution, the people who worked on the patch, any relevant
|
||||||
|
effects on performance, and anything else that might be needed to
|
||||||
|
understand the patch.
|
||||||
|
|
||||||
|
Any code which adds a new user-space interface - including new sysfs or
|
||||||
|
/proc files - should include documentation of that interface which enables
|
||||||
|
user-space developers to know what they are working with. See
|
||||||
|
Documentation/ABI/README for a description of how this documentation should
|
||||||
|
be formatted and what information needs to be provided.
|
||||||
|
|
||||||
|
The file Documentation/kernel-parameters.txt describes all of the kernel's
|
||||||
|
boot-time parameters. Any patch which adds new parameters should add the
|
||||||
|
appropriate entries to this file.
|
||||||
|
|
||||||
|
Any new configuration options must be accompanied by help text which
|
||||||
|
clearly explains the options and when the user might want to select them.
|
||||||
|
|
||||||
|
Internal API information for many subsystems is documented by way of
|
||||||
|
specially-formatted comments; these comments can be extracted and formatted
|
||||||
|
in a number of ways by the "kernel-doc" script. If you are working within
|
||||||
|
a subsystem which has kerneldoc comments, you should maintain them and add
|
||||||
|
them, as appropriate, for externally-available functions. Even in areas
|
||||||
|
which have not been so documented, there is no harm in adding kerneldoc
|
||||||
|
comments for the future; indeed, this can be a useful activity for
|
||||||
|
beginning kernel developers. The format of these comments, along with some
|
||||||
|
information on how to create kerneldoc templates can be found in the file
|
||||||
|
Documentation/kernel-doc-nano-HOWTO.txt.
|
||||||
|
|
||||||
|
Anybody who reads through a significant amount of existing kernel code will
|
||||||
|
note that, often, comments are most notable by their absence. Once again,
|
||||||
|
the expectations for new code are higher than they were in the past;
|
||||||
|
merging uncommented code will be harder. That said, there is little desire
|
||||||
|
for verbosely-commented code. The code should, itself, be readable, with
|
||||||
|
comments explaining the more subtle aspects.
|
||||||
|
|
||||||
|
Certain things should always be commented. Uses of memory barriers should
|
||||||
|
be accompanied by a line explaining why the barrier is necessary. The
|
||||||
|
locking rules for data structures generally need to be explained somewhere.
|
||||||
|
Major data structures need comprehensive documentation in general.
|
||||||
|
Non-obvious dependencies between separate bits of code should be pointed
|
||||||
|
out. Anything which might tempt a code janitor to make an incorrect
|
||||||
|
"cleanup" needs a comment saying why it is done the way it is. And so on.
|
||||||
|
|
||||||
|
|
||||||
|
4.4: INTERNAL API CHANGES
|
||||||
|
|
||||||
|
The binary interface provided by the kernel to user space cannot be broken
|
||||||
|
except under the most severe circumstances. The kernel's internal
|
||||||
|
programming interfaces, instead, are highly fluid and can be changed when
|
||||||
|
the need arises. If you find yourself having to work around a kernel API,
|
||||||
|
or simply not using a specific functionality because it does not meet your
|
||||||
|
needs, that may be a sign that the API needs to change. As a kernel
|
||||||
|
developer, you are empowered to make such changes.
|
||||||
|
|
||||||
|
There are, of course, some catches. API changes can be made, but they need
|
||||||
|
to be well justified. So any patch making an internal API change should be
|
||||||
|
accompanied by a description of what the change is and why it is
|
||||||
|
necessary. This kind of change should also be broken out into a separate
|
||||||
|
patch, rather than buried within a larger patch.
|
||||||
|
|
||||||
|
The other catch is that a developer who changes an internal API is
|
||||||
|
generally charged with the task of fixing any code within the kernel tree
|
||||||
|
which is broken by the change. For a widely-used function, this duty can
|
||||||
|
lead to literally hundreds or thousands of changes - many of which are
|
||||||
|
likely to conflict with work being done by other developers. Needless to
|
||||||
|
say, this can be a large job, so it is best to be sure that the
|
||||||
|
justification is solid.
|
||||||
|
|
||||||
|
When making an incompatible API change, one should, whenever possible,
|
||||||
|
ensure that code which has not been updated is caught by the compiler.
|
||||||
|
This will help you to be sure that you have found all in-tree uses of that
|
||||||
|
interface. It will also alert developers of out-of-tree code that there is
|
||||||
|
a change that they need to respond to. Supporting out-of-tree code is not
|
||||||
|
something that kernel developers need to be worried about, but we also do
|
||||||
|
not have to make life harder for out-of-tree developers than it it needs to
|
||||||
|
be.
|
|
@ -0,0 +1,278 @@
|
||||||
|
5: POSTING PATCHES
|
||||||
|
|
||||||
|
Sooner or later, the time comes when your work is ready to be presented to
|
||||||
|
the community for review and, eventually, inclusion into the mainline
|
||||||
|
kernel. Unsurprisingly, the kernel development community has evolved a set
|
||||||
|
of conventions and procedures which are used in the posting of patches;
|
||||||
|
following them will make life much easier for everybody involved. This
|
||||||
|
document will attempt to cover these expectations in reasonable detail;
|
||||||
|
more information can also be found in the files SubmittingPatches,
|
||||||
|
SubmittingDrivers, and SubmitChecklist in the kernel documentation
|
||||||
|
directory.
|
||||||
|
|
||||||
|
|
||||||
|
5.1: WHEN TO POST
|
||||||
|
|
||||||
|
There is a constant temptation to avoid posting patches before they are
|
||||||
|
completely "ready." For simple patches, that is not a problem. If the
|
||||||
|
work being done is complex, though, there is a lot to be gained by getting
|
||||||
|
feedback from the community before the work is complete. So you should
|
||||||
|
consider posting in-progress work, or even making a git tree available so
|
||||||
|
that interested developers can catch up with your work at any time.
|
||||||
|
|
||||||
|
When posting code which is not yet considered ready for inclusion, it is a
|
||||||
|
good idea to say so in the posting itself. Also mention any major work
|
||||||
|
which remains to be done and any known problems. Fewer people will look at
|
||||||
|
patches which are known to be half-baked, but those who do will come in
|
||||||
|
with the idea that they can help you drive the work in the right direction.
|
||||||
|
|
||||||
|
|
||||||
|
5.2: BEFORE CREATING PATCHES
|
||||||
|
|
||||||
|
There are a number of things which should be done before you consider
|
||||||
|
sending patches to the development community. These include:
|
||||||
|
|
||||||
|
- Test the code to the extent that you can. Make use of the kernel's
|
||||||
|
debugging tools, ensure that the kernel will build with all reasonable
|
||||||
|
combinations of configuration options, use cross-compilers to build for
|
||||||
|
different architectures, etc.
|
||||||
|
|
||||||
|
- Make sure your code is compliant with the kernel coding style
|
||||||
|
guidelines.
|
||||||
|
|
||||||
|
- Does your change have performance implications? If so, you should run
|
||||||
|
benchmarks showing what the impact (or benefit) of your change is; a
|
||||||
|
summary of the results should be included with the patch.
|
||||||
|
|
||||||
|
- Be sure that you have the right to post the code. If this work was done
|
||||||
|
for an employer, the employer likely has a right to the work and must be
|
||||||
|
agreeable with its release under the GPL.
|
||||||
|
|
||||||
|
As a general rule, putting in some extra thought before posting code almost
|
||||||
|
always pays back the effort in short order.
|
||||||
|
|
||||||
|
|
||||||
|
5.3: PATCH PREPARATION
|
||||||
|
|
||||||
|
The preparation of patches for posting can be a surprising amount of work,
|
||||||
|
but, once again, attempting to save time here is not generally advisable
|
||||||
|
even in the short term.
|
||||||
|
|
||||||
|
Patches must be prepared against a specific version of the kernel. As a
|
||||||
|
general rule, a patch should be based on the current mainline as found in
|
||||||
|
Linus's git tree. It may become necessary to make versions against -mm,
|
||||||
|
linux-next, or a subsystem tree, though, to facilitate wider testing and
|
||||||
|
review. Depending on the area of your patch and what is going on
|
||||||
|
elsewhere, basing a patch against these other trees can require a
|
||||||
|
significant amount of work resolving conflicts and dealing with API
|
||||||
|
changes.
|
||||||
|
|
||||||
|
Only the most simple changes should be formatted as a single patch;
|
||||||
|
everything else should be made as a logical series of changes. Splitting
|
||||||
|
up patches is a bit of an art; some developers spend a long time figuring
|
||||||
|
out how to do it in the way that the community expects. There are a few
|
||||||
|
rules of thumb, however, which can help considerably:
|
||||||
|
|
||||||
|
- The patch series you post will almost certainly not be the series of
|
||||||
|
changes found in your working revision control system. Instead, the
|
||||||
|
changes you have made need to be considered in their final form, then
|
||||||
|
split apart in ways which make sense. The developers are interested in
|
||||||
|
discrete, self-contained changes, not the path you took to get to those
|
||||||
|
changes.
|
||||||
|
|
||||||
|
- Each logically independent change should be formatted as a separate
|
||||||
|
patch. These changes can be small ("add a field to this structure") or
|
||||||
|
large (adding a significant new driver, for example), but they should be
|
||||||
|
conceptually small and amenable to a one-line description. Each patch
|
||||||
|
should make a specific change which can be reviewed on its own and
|
||||||
|
verified to do what it says it does.
|
||||||
|
|
||||||
|
- As a way of restating the guideline above: do not mix different types of
|
||||||
|
changes in the same patch. If a single patch fixes a critical security
|
||||||
|
bug, rearranges a few structures, and reformats the code, there is a
|
||||||
|
good chance that it will be passed over and the important fix will be
|
||||||
|
lost.
|
||||||
|
|
||||||
|
- Each patch should yield a kernel which builds and runs properly; if your
|
||||||
|
patch series is interrupted in the middle, the result should still be a
|
||||||
|
working kernel. Partial application of a patch series is a common
|
||||||
|
scenario when the "git bisect" tool is used to find regressions; if the
|
||||||
|
result is a broken kernel, you will make life harder for developers and
|
||||||
|
users who are engaging in the noble work of tracking down problems.
|
||||||
|
|
||||||
|
- Do not overdo it, though. One developer recently posted a set of edits
|
||||||
|
to a single file as 500 separate patches - an act which did not make him
|
||||||
|
the most popular person on the kernel mailing list. A single patch can
|
||||||
|
be reasonably large as long as it still contains a single *logical*
|
||||||
|
change.
|
||||||
|
|
||||||
|
- It can be tempting to add a whole new infrastructure with a series of
|
||||||
|
patches, but to leave that infrastructure unused until the final patch
|
||||||
|
in the series enables the whole thing. This temptation should be
|
||||||
|
avoided if possible; if that series adds regressions, bisection will
|
||||||
|
finger the last patch as the one which caused the problem, even though
|
||||||
|
the real bug is elsewhere. Whenever possible, a patch which adds new
|
||||||
|
code should make that code active immediately.
|
||||||
|
|
||||||
|
Working to create the perfect patch series can be a frustrating process
|
||||||
|
which takes quite a bit of time and thought after the "real work" has been
|
||||||
|
done. When done properly, though, it is time well spent.
|
||||||
|
|
||||||
|
|
||||||
|
5.4: PATCH FORMATTING
|
||||||
|
|
||||||
|
So now you have a perfect series of patches for posting, but the work is
|
||||||
|
not done quite yet. Each patch needs to be formatted into a message which
|
||||||
|
quickly and clearly communicates its purpose to the rest of the world. To
|
||||||
|
that end, each patch will be composed of the following:
|
||||||
|
|
||||||
|
- An optional "From" line naming the author of the patch. This line is
|
||||||
|
only necessary if you are passing on somebody else's patch via email,
|
||||||
|
but it never hurts to add it when in doubt.
|
||||||
|
|
||||||
|
- A one-line description of what the patch does. This message should be
|
||||||
|
enough for a reader who sees it with no other context to figure out the
|
||||||
|
scope of the patch; it is the line that will show up in the "short form"
|
||||||
|
changelogs. This message is usually formatted with the relevant
|
||||||
|
subsystem name first, followed by the purpose of the patch. For
|
||||||
|
example:
|
||||||
|
|
||||||
|
gpio: fix build on CONFIG_GPIO_SYSFS=n
|
||||||
|
|
||||||
|
- A blank line followed by a detailed description of the contents of the
|
||||||
|
patch. This description can be as long as is required; it should say
|
||||||
|
what the patch does and why it should be applied to the kernel.
|
||||||
|
|
||||||
|
- One or more tag lines, with, at a minimum, one Signed-off-by: line from
|
||||||
|
the author of the patch. Tags will be described in more detail below.
|
||||||
|
|
||||||
|
The above three items should, normally, be the text used when committing
|
||||||
|
the change to a revision control system. They are followed by:
|
||||||
|
|
||||||
|
- The patch itself, in the unified ("-u") patch format. Using the "-p"
|
||||||
|
option to diff will associate function names with changes, making the
|
||||||
|
resulting patch easier for others to read.
|
||||||
|
|
||||||
|
You should avoid including changes to irrelevant files (those generated by
|
||||||
|
the build process, for example, or editor backup files) in the patch. The
|
||||||
|
file "dontdiff" in the Documentation directory can help in this regard;
|
||||||
|
pass it to diff with the "-X" option.
|
||||||
|
|
||||||
|
The tags mentioned above are used to describe how various developers have
|
||||||
|
been associated with the development of this patch. They are described in
|
||||||
|
detail in the SubmittingPatches document; what follows here is a brief
|
||||||
|
summary. Each of these lines has the format:
|
||||||
|
|
||||||
|
tag: Full Name <email address> optional-other-stuff
|
||||||
|
|
||||||
|
The tags in common use are:
|
||||||
|
|
||||||
|
- Signed-off-by: this is a developer's certification that he or she has
|
||||||
|
the right to submit the patch for inclusion into the kernel. It is an
|
||||||
|
agreement to the Developer's Certificate of Origin, the full text of
|
||||||
|
which can be found in Documentation/SubmittingPatches. Code without a
|
||||||
|
proper signoff cannot be merged into the mainline.
|
||||||
|
|
||||||
|
- Acked-by: indicates an agreement by another developer (often a
|
||||||
|
maintainer of the relevant code) that the patch is appropriate for
|
||||||
|
inclusion into the kernel.
|
||||||
|
|
||||||
|
- Tested-by: states that the named person has tested the patch and found
|
||||||
|
it to work.
|
||||||
|
|
||||||
|
- Reviewed-by: the named developer has reviewed the patch for correctness;
|
||||||
|
see the reviewer's statement in Documentation/SubmittingPatches for more
|
||||||
|
detail.
|
||||||
|
|
||||||
|
- Reported-by: names a user who reported a problem which is fixed by this
|
||||||
|
patch; this tag is used to give credit to the (often underappreciated)
|
||||||
|
people who test our code and let us know when things do not work
|
||||||
|
correctly.
|
||||||
|
|
||||||
|
- Cc: the named person received a copy of the patch and had the
|
||||||
|
opportunity to comment on it.
|
||||||
|
|
||||||
|
Be careful in the addition of tags to your patches: only Cc: is appropriate
|
||||||
|
for addition without the explicit permission of the person named.
|
||||||
|
|
||||||
|
|
||||||
|
5.5: SENDING THE PATCH
|
||||||
|
|
||||||
|
Before you mail your patches, there are a couple of other things you should
|
||||||
|
take care of:
|
||||||
|
|
||||||
|
- Are you sure that your mailer will not corrupt the patches? Patches
|
||||||
|
which have had gratuitous white-space changes or line wrapping performed
|
||||||
|
by the mail client will not apply at the other end, and often will not
|
||||||
|
be examined in any detail. If there is any doubt at all, mail the patch
|
||||||
|
to yourself and convince yourself that it shows up intact.
|
||||||
|
|
||||||
|
Documentation/email-clients.txt has some helpful hints on making
|
||||||
|
specific mail clients work for sending patches.
|
||||||
|
|
||||||
|
- Are you sure your patch is free of silly mistakes? You should always
|
||||||
|
run patches through scripts/checkpatch.pl and address the complaints it
|
||||||
|
comes up with. Please bear in mind that checkpatch.pl, while being the
|
||||||
|
embodiment of a fair amount of thought about what kernel patches should
|
||||||
|
look like, is not smarter than you. If fixing a checkpatch.pl complaint
|
||||||
|
would make the code worse, don't do it.
|
||||||
|
|
||||||
|
Patches should always be sent as plain text. Please do not send them as
|
||||||
|
attachments; that makes it much harder for reviewers to quote sections of
|
||||||
|
the patch in their replies. Instead, just put the patch directly into your
|
||||||
|
message.
|
||||||
|
|
||||||
|
When mailing patches, it is important to send copies to anybody who might
|
||||||
|
be interested in it. Unlike some other projects, the kernel encourages
|
||||||
|
people to err on the side of sending too many copies; don't assume that the
|
||||||
|
relevant people will see your posting on the mailing lists. In particular,
|
||||||
|
copies should go to:
|
||||||
|
|
||||||
|
- The maintainer(s) of the affected subsystem(s). As described earlier,
|
||||||
|
the MAINTAINERS file is the first place to look for these people.
|
||||||
|
|
||||||
|
- Other developers who have been working in the same area - especially
|
||||||
|
those who might be working there now. Using git to see who else has
|
||||||
|
modified the files you are working on can be helpful.
|
||||||
|
|
||||||
|
- If you are responding to a bug report or a feature request, copy the
|
||||||
|
original poster as well.
|
||||||
|
|
||||||
|
- Send a copy to the relevant mailing list, or, if nothing else applies,
|
||||||
|
the linux-kernel list.
|
||||||
|
|
||||||
|
- If you are fixing a bug, think about whether the fix should go into the
|
||||||
|
next stable update. If so, stable@kernel.org should get a copy of the
|
||||||
|
patch. Also add a "Cc: stable@kernel.org" to the tags within the patch
|
||||||
|
itself; that will cause the stable team to get a notification when your
|
||||||
|
fix goes into the mainline.
|
||||||
|
|
||||||
|
When selecting recipients for a patch, it is good to have an idea of who
|
||||||
|
you think will eventually accept the patch and get it merged. While it
|
||||||
|
is possible to send patches directly to Linus Torvalds and have him merge
|
||||||
|
them, things are not normally done that way. Linus is busy, and there are
|
||||||
|
subsystem maintainers who watch over specific parts of the kernel. Usually
|
||||||
|
you will be wanting that maintainer to merge your patches. If there is no
|
||||||
|
obvious maintainer, Andrew Morton is often the patch target of last resort.
|
||||||
|
|
||||||
|
Patches need good subject lines. The canonical format for a patch line is
|
||||||
|
something like:
|
||||||
|
|
||||||
|
[PATCH nn/mm] subsys: one-line description of the patch
|
||||||
|
|
||||||
|
where "nn" is the ordinal number of the patch, "mm" is the total number of
|
||||||
|
patches in the series, and "subsys" is the name of the affected subsystem.
|
||||||
|
Clearly, nn/mm can be omitted for a single, standalone patch.
|
||||||
|
|
||||||
|
If you have a significant series of patches, it is customary to send an
|
||||||
|
introductory description as part zero. This convention is not universally
|
||||||
|
followed though; if you use it, remember that information in the
|
||||||
|
introduction does not make it into the kernel changelogs. So please ensure
|
||||||
|
that the patches, themselves, have complete changelog information.
|
||||||
|
|
||||||
|
In general, the second and following parts of a multi-part patch should be
|
||||||
|
sent as a reply to the first part so that they all thread together at the
|
||||||
|
receiving end. Tools like git and quilt have commands to mail out a set of
|
||||||
|
patches with the proper threading. If you have a long series, though, and
|
||||||
|
are using git, please provide the --no-chain-reply-to option to avoid
|
||||||
|
creating exceptionally deep nesting.
|
|
@ -0,0 +1,202 @@
|
||||||
|
6: FOLLOWTHROUGH
|
||||||
|
|
||||||
|
At this point, you have followed the guidelines given so far and, with the
|
||||||
|
addition of your own engineering skills, have posted a perfect series of
|
||||||
|
patches. One of the biggest mistakes that even experienced kernel
|
||||||
|
developers can make is to conclude that their work is now done. In truth,
|
||||||
|
posting patches indicates a transition into the next stage of the process,
|
||||||
|
with, possibly, quite a bit of work yet to be done.
|
||||||
|
|
||||||
|
It is a rare patch which is so good at its first posting that there is no
|
||||||
|
room for improvement. The kernel development process recognizes this fact,
|
||||||
|
and, as a result, is heavily oriented toward the improvement of posted
|
||||||
|
code. You, as the author of that code, will be expected to work with the
|
||||||
|
kernel community to ensure that your code is up to the kernel's quality
|
||||||
|
standards. A failure to participate in this process is quite likely to
|
||||||
|
prevent the inclusion of your patches into the mainline.
|
||||||
|
|
||||||
|
|
||||||
|
6.1: WORKING WITH REVIEWERS
|
||||||
|
|
||||||
|
A patch of any significance will result in a number of comments from other
|
||||||
|
developers as they review the code. Working with reviewers can be, for
|
||||||
|
many developers, the most intimidating part of the kernel development
|
||||||
|
process. Life can be made much easier, though, if you keep a few things in
|
||||||
|
mind:
|
||||||
|
|
||||||
|
- If you have explained your patch well, reviewers will understand its
|
||||||
|
value and why you went to the trouble of writing it. But that value
|
||||||
|
will not keep them from asking a fundamental question: what will it be
|
||||||
|
like to maintain a kernel with this code in it five or ten years later?
|
||||||
|
Many of the changes you may be asked to make - from coding style tweaks
|
||||||
|
to substantial rewrites - come from the understanding that Linux will
|
||||||
|
still be around and under development a decade from now.
|
||||||
|
|
||||||
|
- Code review is hard work, and it is a relatively thankless occupation;
|
||||||
|
people remember who wrote kernel code, but there is little lasting fame
|
||||||
|
for those who reviewed it. So reviewers can get grumpy, especially when
|
||||||
|
they see the same mistakes being made over and over again. If you get a
|
||||||
|
review which seems angry, insulting, or outright offensive, resist the
|
||||||
|
impulse to respond in kind. Code review is about the code, not about
|
||||||
|
the people, and code reviewers are not attacking you personally.
|
||||||
|
|
||||||
|
- Similarly, code reviewers are not trying to promote their employers'
|
||||||
|
agendas at the expense of your own. Kernel developers often expect to
|
||||||
|
be working on the kernel years from now, but they understand that their
|
||||||
|
employer could change. They truly are, almost without exception,
|
||||||
|
working toward the creation of the best kernel they can; they are not
|
||||||
|
trying to create discomfort for their employers' competitors.
|
||||||
|
|
||||||
|
What all of this comes down to is that, when reviewers send you comments,
|
||||||
|
you need to pay attention to the technical observations that they are
|
||||||
|
making. Do not let their form of expression or your own pride keep that
|
||||||
|
from happening. When you get review comments on a patch, take the time to
|
||||||
|
understand what the reviewer is trying to say. If possible, fix the things
|
||||||
|
that the reviewer is asking you to fix. And respond back to the reviewer:
|
||||||
|
thank them, and describe how you will answer their questions.
|
||||||
|
|
||||||
|
Note that you do not have to agree with every change suggested by
|
||||||
|
reviewers. If you believe that the reviewer has misunderstood your code,
|
||||||
|
explain what is really going on. If you have a technical objection to a
|
||||||
|
suggested change, describe it and justify your solution to the problem. If
|
||||||
|
your explanations make sense, the reviewer will accept them. Should your
|
||||||
|
explanation not prove persuasive, though, especially if others start to
|
||||||
|
agree with the reviewer, take some time to think things over again. It can
|
||||||
|
be easy to become blinded by your own solution to a problem to the point
|
||||||
|
that you don't realize that something is fundamentally wrong or, perhaps,
|
||||||
|
you're not even solving the right problem.
|
||||||
|
|
||||||
|
One fatal mistake is to ignore review comments in the hope that they will
|
||||||
|
go away. They will not go away. If you repost code without having
|
||||||
|
responded to the comments you got the time before, you're likely to find
|
||||||
|
that your patches go nowhere.
|
||||||
|
|
||||||
|
Speaking of reposting code: please bear in mind that reviewers are not
|
||||||
|
going to remember all the details of the code you posted the last time
|
||||||
|
around. So it is always a good idea to remind reviewers of previously
|
||||||
|
raised issues and how you dealt with them; the patch changelog is a good
|
||||||
|
place for this kind of information. Reviewers should not have to search
|
||||||
|
through list archives to familiarize themselves with what was said last
|
||||||
|
time; if you help them get a running start, they will be in a better mood
|
||||||
|
when they revisit your code.
|
||||||
|
|
||||||
|
What if you've tried to do everything right and things still aren't going
|
||||||
|
anywhere? Most technical disagreements can be resolved through discussion,
|
||||||
|
but there are times when somebody simply has to make a decision. If you
|
||||||
|
honestly believe that this decision is going against you wrongly, you can
|
||||||
|
always try appealing to a higher power. As of this writing, that higher
|
||||||
|
power tends to be Andrew Morton. Andrew has a great deal of respect in the
|
||||||
|
kernel development community; he can often unjam a situation which seems to
|
||||||
|
be hopelessly blocked. Appealing to Andrew should not be done lightly,
|
||||||
|
though, and not before all other alternatives have been explored. And bear
|
||||||
|
in mind, of course, that he may not agree with you either.
|
||||||
|
|
||||||
|
|
||||||
|
6.2: WHAT HAPPENS NEXT
|
||||||
|
|
||||||
|
If a patch is considered to be a good thing to add to the kernel, and once
|
||||||
|
most of the review issues have been resolved, the next step is usually
|
||||||
|
entry into a subsystem maintainer's tree. How that works varies from one
|
||||||
|
subsystem to the next; each maintainer has his or her own way of doing
|
||||||
|
things. In particular, there may be more than one tree - one, perhaps,
|
||||||
|
dedicated to patches planned for the next merge window, and another for
|
||||||
|
longer-term work.
|
||||||
|
|
||||||
|
For patches applying to areas for which there is no obvious subsystem tree
|
||||||
|
(memory management patches, for example), the default tree often ends up
|
||||||
|
being -mm. Patches which affect multiple subsystems can also end up going
|
||||||
|
through the -mm tree.
|
||||||
|
|
||||||
|
Inclusion into a subsystem tree can bring a higher level of visibility to a
|
||||||
|
patch. Now other developers working with that tree will get the patch by
|
||||||
|
default. Subsystem trees typically feed into -mm and linux-next as well,
|
||||||
|
making their contents visible to the development community as a whole. At
|
||||||
|
this point, there's a good chance that you will get more comments from a
|
||||||
|
new set of reviewers; these comments need to be answered as in the previous
|
||||||
|
round.
|
||||||
|
|
||||||
|
What may also happen at this point, depending on the nature of your patch,
|
||||||
|
is that conflicts with work being done by others turn up. In the worst
|
||||||
|
case, heavy patch conflicts can result in some work being put on the back
|
||||||
|
burner so that the remaining patches can be worked into shape and merged.
|
||||||
|
Other times, conflict resolution will involve working with the other
|
||||||
|
developers and, possibly, moving some patches between trees to ensure that
|
||||||
|
everything applies cleanly. This work can be a pain, but count your
|
||||||
|
blessings: before the advent of the linux-next tree, these conflicts often
|
||||||
|
only turned up during the merge window and had to be addressed in a hurry.
|
||||||
|
Now they can be resolved at leisure, before the merge window opens.
|
||||||
|
|
||||||
|
Some day, if all goes well, you'll log on and see that your patch has been
|
||||||
|
merged into the mainline kernel. Congratulations! Once the celebration is
|
||||||
|
complete (and you have added yourself to the MAINTAINERS file), though, it
|
||||||
|
is worth remembering an important little fact: the job still is not done.
|
||||||
|
Merging into the mainline brings its own challenges.
|
||||||
|
|
||||||
|
To begin with, the visibility of your patch has increased yet again. There
|
||||||
|
may be a new round of comments from developers who had not been aware of
|
||||||
|
the patch before. It may be tempting to ignore them, since there is no
|
||||||
|
longer any question of your code being merged. Resist that temptation,
|
||||||
|
though; you still need to be responsive to developers who have questions or
|
||||||
|
suggestions.
|
||||||
|
|
||||||
|
More importantly, though: inclusion into the mainline puts your code into
|
||||||
|
the hands of a much larger group of testers. Even if you have contributed
|
||||||
|
a driver for hardware which is not yet available, you will be surprised by
|
||||||
|
how many people will build your code into their kernels. And, of course,
|
||||||
|
where there are testers, there will be bug reports.
|
||||||
|
|
||||||
|
The worst sort of bug reports are regressions. If your patch causes a
|
||||||
|
regression, you'll find an uncomfortable number of eyes upon you;
|
||||||
|
regressions need to be fixed as soon as possible. If you are unwilling or
|
||||||
|
unable to fix the regression (and nobody else does it for you), your patch
|
||||||
|
will almost certainly be removed during the stabilization period. Beyond
|
||||||
|
negating all of the work you have done to get your patch into the mainline,
|
||||||
|
having a patch pulled as the result of a failure to fix a regression could
|
||||||
|
well make it harder for you to get work merged in the future.
|
||||||
|
|
||||||
|
After any regressions have been dealt with, there may be other, ordinary
|
||||||
|
bugs to deal with. The stabilization period is your best opportunity to
|
||||||
|
fix these bugs and ensure that your code's debut in a mainline kernel
|
||||||
|
release is as solid as possible. So, please, answer bug reports, and fix
|
||||||
|
the problems if at all possible. That's what the stabilization period is
|
||||||
|
for; you can start creating cool new patches once any problems with the old
|
||||||
|
ones have been taken care of.
|
||||||
|
|
||||||
|
And don't forget that there are other milestones which may also create bug
|
||||||
|
reports: the next mainline stable release, when prominent distributors pick
|
||||||
|
up a version of the kernel containing your patch, etc. Continuing to
|
||||||
|
respond to these reports is a matter of basic pride in your work. If that
|
||||||
|
is insufficient motivation, though, it's also worth considering that the
|
||||||
|
development community remembers developers who lose interest in their code
|
||||||
|
after it's merged. The next time you post a patch, they will be evaluating
|
||||||
|
it with the assumption that you will not be around to maintain it
|
||||||
|
afterward.
|
||||||
|
|
||||||
|
|
||||||
|
6.3: OTHER THINGS THAT CAN HAPPEN
|
||||||
|
|
||||||
|
One day, you may open your mail client and see that somebody has mailed you
|
||||||
|
a patch to your code. That is one of the advantages of having your code
|
||||||
|
out there in the open, after all. If you agree with the patch, you can
|
||||||
|
either forward it on to the subsystem maintainer (be sure to include a
|
||||||
|
proper From: line so that the attribution is correct, and add a signoff of
|
||||||
|
your own), or send an Acked-by: response back and let the original poster
|
||||||
|
send it upward.
|
||||||
|
|
||||||
|
If you disagree with the patch, send a polite response explaining why. If
|
||||||
|
possible, tell the author what changes need to be made to make the patch
|
||||||
|
acceptable to you. There is a certain resistance to merging patches which
|
||||||
|
are opposed by the author and maintainer of the code, but it only goes so
|
||||||
|
far. If you are seen as needlessly blocking good work, those patches will
|
||||||
|
eventually flow around you and get into the mainline anyway. In the Linux
|
||||||
|
kernel, nobody has absolute veto power over any code. Except maybe Linus.
|
||||||
|
|
||||||
|
On very rare occasion, you may see something completely different: another
|
||||||
|
developer posts a different solution to your problem. At that point,
|
||||||
|
chances are that one of the two patches will not be merged, and "mine was
|
||||||
|
here first" is not considered to be a compelling technical argument. If
|
||||||
|
somebody else's patch displaces yours and gets into the mainline, there is
|
||||||
|
really only one way to respond: be pleased that your problem got solved and
|
||||||
|
get on with your work. Having one's work shoved aside in this manner can
|
||||||
|
be hurtful and discouraging, but the community will remember your reaction
|
||||||
|
long after they have forgotten whose patch actually got merged.
|
|
@ -0,0 +1,173 @@
|
||||||
|
7: ADVANCED TOPICS
|
||||||
|
|
||||||
|
At this point, hopefully, you have a handle on how the development process
|
||||||
|
works. There is still more to learn, however! This section will cover a
|
||||||
|
number of topics which can be helpful for developers wanting to become a
|
||||||
|
regular part of the Linux kernel development process.
|
||||||
|
|
||||||
|
7.1: MANAGING PATCHES WITH GIT
|
||||||
|
|
||||||
|
The use of distributed version control for the kernel began in early 2002,
|
||||||
|
when Linus first started playing with the proprietary BitKeeper
|
||||||
|
application. While BitKeeper was controversial, the approach to software
|
||||||
|
version management it embodied most certainly was not. Distributed version
|
||||||
|
control enabled an immediate acceleration of the kernel development
|
||||||
|
project. In current times, there are several free alternatives to
|
||||||
|
BitKeeper. For better or for worse, the kernel project has settled on git
|
||||||
|
as its tool of choice.
|
||||||
|
|
||||||
|
Managing patches with git can make life much easier for the developer,
|
||||||
|
especially as the volume of those patches grows. Git also has its rough
|
||||||
|
edges and poses certain hazards; it is a young and powerful tool which is
|
||||||
|
still being civilized by its developers. This document will not attempt to
|
||||||
|
teach the reader how to use git; that would be sufficient material for a
|
||||||
|
long document in its own right. Instead, the focus here will be on how git
|
||||||
|
fits into the kernel development process in particular. Developers who
|
||||||
|
wish to come up to speed with git will find more information at:
|
||||||
|
|
||||||
|
http://git.or.cz/
|
||||||
|
|
||||||
|
http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
|
||||||
|
|
||||||
|
and on various tutorials found on the web.
|
||||||
|
|
||||||
|
The first order of business is to read the above sites and get a solid
|
||||||
|
understanding of how git works before trying to use it to make patches
|
||||||
|
available to others. A git-using developer should be able to obtain a copy
|
||||||
|
of the mainline repository, explore the revision history, commit changes to
|
||||||
|
the tree, use branches, etc. An understanding of git's tools for the
|
||||||
|
rewriting of history (such as rebase) is also useful. Git comes with its
|
||||||
|
own terminology and concepts; a new user of git should know about refs,
|
||||||
|
remote branches, the index, fast-forward merges, pushes and pulls, detached
|
||||||
|
heads, etc. It can all be a little intimidating at the outset, but the
|
||||||
|
concepts are not that hard to grasp with a bit of study.
|
||||||
|
|
||||||
|
Using git to generate patches for submission by email can be a good
|
||||||
|
exercise while coming up to speed.
|
||||||
|
|
||||||
|
When you are ready to start putting up git trees for others to look at, you
|
||||||
|
will, of course, need a server that can be pulled from. Setting up such a
|
||||||
|
server with git-daemon is relatively straightforward if you have a system
|
||||||
|
which is accessible to the Internet. Otherwise, free, public hosting sites
|
||||||
|
(Github, for example) are starting to appear on the net. Established
|
||||||
|
developers can get an account on kernel.org, but those are not easy to come
|
||||||
|
by; see http://kernel.org/faq/ for more information.
|
||||||
|
|
||||||
|
The normal git workflow involves the use of a lot of branches. Each line
|
||||||
|
of development can be separated into a separate "topic branch" and
|
||||||
|
maintained independently. Branches in git are cheap, there is no reason to
|
||||||
|
not make free use of them. And, in any case, you should not do your
|
||||||
|
development in any branch which you intend to ask others to pull from.
|
||||||
|
Publicly-available branches should be created with care; merge in patches
|
||||||
|
from development branches when they are in complete form and ready to go -
|
||||||
|
not before.
|
||||||
|
|
||||||
|
Git provides some powerful tools which can allow you to rewrite your
|
||||||
|
development history. An inconvenient patch (one which breaks bisection,
|
||||||
|
say, or which has some other sort of obvious bug) can be fixed in place or
|
||||||
|
made to disappear from the history entirely. A patch series can be
|
||||||
|
rewritten as if it had been written on top of today's mainline, even though
|
||||||
|
you have been working on it for months. Changes can be transparently
|
||||||
|
shifted from one branch to another. And so on. Judicious use of git's
|
||||||
|
ability to revise history can help in the creation of clean patch sets with
|
||||||
|
fewer problems.
|
||||||
|
|
||||||
|
Excessive use of this capability can lead to other problems, though, beyond
|
||||||
|
a simple obsession for the creation of the perfect project history.
|
||||||
|
Rewriting history will rewrite the changes contained in that history,
|
||||||
|
turning a tested (hopefully) kernel tree into an untested one. But, beyond
|
||||||
|
that, developers cannot easily collaborate if they do not have a shared
|
||||||
|
view of the project history; if you rewrite history which other developers
|
||||||
|
have pulled into their repositories, you will make life much more difficult
|
||||||
|
for those developers. So a simple rule of thumb applies here: history
|
||||||
|
which has been exported to others should generally be seen as immutable
|
||||||
|
thereafter.
|
||||||
|
|
||||||
|
So, once you push a set of changes to your publicly-available server, those
|
||||||
|
changes should not be rewritten. Git will attempt to enforce this rule if
|
||||||
|
you try to push changes which do not result in a fast-forward merge
|
||||||
|
(i.e. changes which do not share the same history). It is possible to
|
||||||
|
override this check, and there may be times when it is necessary to rewrite
|
||||||
|
an exported tree. Moving changesets between trees to avoid conflicts in
|
||||||
|
linux-next is one example. But such actions should be rare. This is one
|
||||||
|
of the reasons why development should be done in private branches (which
|
||||||
|
can be rewritten if necessary) and only moved into public branches when
|
||||||
|
it's in a reasonably advanced state.
|
||||||
|
|
||||||
|
As the mainline (or other tree upon which a set of changes is based)
|
||||||
|
advances, it is tempting to merge with that tree to stay on the leading
|
||||||
|
edge. For a private branch, rebasing can be an easy way to keep up with
|
||||||
|
another tree, but rebasing is not an option once a tree is exported to the
|
||||||
|
world. Once that happens, a full merge must be done. Merging occasionally
|
||||||
|
makes good sense, but overly frequent merges can clutter the history
|
||||||
|
needlessly. Suggested technique in this case is to merge infrequently, and
|
||||||
|
generally only at specific release points (such as a mainline -rc
|
||||||
|
release). If you are nervous about specific changes, you can always
|
||||||
|
perform test merges in a private branch. The git "rerere" tool can be
|
||||||
|
useful in such situations; it remembers how merge conflicts were resolved
|
||||||
|
so that you don't have to do the same work twice.
|
||||||
|
|
||||||
|
One of the biggest recurring complaints about tools like git is this: the
|
||||||
|
mass movement of patches from one repository to another makes it easy to
|
||||||
|
slip in ill-advised changes which go into the mainline below the review
|
||||||
|
radar. Kernel developers tend to get unhappy when they see that kind of
|
||||||
|
thing happening; putting up a git tree with unreviewed or off-topic patches
|
||||||
|
can affect your ability to get trees pulled in the future. Quoting Linus:
|
||||||
|
|
||||||
|
You can send me patches, but for me to pull a git patch from you, I
|
||||||
|
need to know that you know what you're doing, and I need to be able
|
||||||
|
to trust things *without* then having to go and check every
|
||||||
|
individual change by hand.
|
||||||
|
|
||||||
|
(http://lwn.net/Articles/224135/).
|
||||||
|
|
||||||
|
To avoid this kind of situation, ensure that all patches within a given
|
||||||
|
branch stick closely to the associated topic; a "driver fixes" branch
|
||||||
|
should not be making changes to the core memory management code. And, most
|
||||||
|
importantly, do not use a git tree to bypass the review process. Post an
|
||||||
|
occasional summary of the tree to the relevant list, and, when the time is
|
||||||
|
right, request that the tree be included in linux-next.
|
||||||
|
|
||||||
|
If and when others start to send patches for inclusion into your tree,
|
||||||
|
don't forget to review them. Also ensure that you maintain the correct
|
||||||
|
authorship information; the git "am" tool does its best in this regard, but
|
||||||
|
you may have to add a "From:" line to the patch if it has been relayed to
|
||||||
|
you via a third party.
|
||||||
|
|
||||||
|
When requesting a pull, be sure to give all the relevant information: where
|
||||||
|
your tree is, what branch to pull, and what changes will result from the
|
||||||
|
pull. The git request-pull command can be helpful in this regard; it will
|
||||||
|
format the request as other developers expect, and will also check to be
|
||||||
|
sure that you have remembered to push those changes to the public server.
|
||||||
|
|
||||||
|
|
||||||
|
7.2: REVIEWING PATCHES
|
||||||
|
|
||||||
|
Some readers will certainly object to putting this section with "advanced
|
||||||
|
topics" on the grounds that even beginning kernel developers should be
|
||||||
|
reviewing patches. It is certainly true that there is no better way to
|
||||||
|
learn how to program in the kernel environment than by looking at code
|
||||||
|
posted by others. In addition, reviewers are forever in short supply; by
|
||||||
|
looking at code you can make a significant contribution to the process as a
|
||||||
|
whole.
|
||||||
|
|
||||||
|
Reviewing code can be an intimidating prospect, especially for a new kernel
|
||||||
|
developer who may well feel nervous about questioning code - in public -
|
||||||
|
which has been posted by those with more experience. Even code written by
|
||||||
|
the most experienced developers can be improved, though. Perhaps the best
|
||||||
|
piece of advice for reviewers (all reviewers) is this: phrase review
|
||||||
|
comments as questions rather than criticisms. Asking "how does the lock
|
||||||
|
get released in this path?" will always work better than stating "the
|
||||||
|
locking here is wrong."
|
||||||
|
|
||||||
|
Different developers will review code from different points of view. Some
|
||||||
|
are mostly concerned with coding style and whether code lines have trailing
|
||||||
|
white space. Others will focus primarily on whether the change implemented
|
||||||
|
by the patch as a whole is a good thing for the kernel or not. Yet others
|
||||||
|
will check for problematic locking, excessive stack usage, possible
|
||||||
|
security issues, duplication of code found elsewhere, adequate
|
||||||
|
documentation, adverse effects on performance, user-space ABI changes, etc.
|
||||||
|
All types of review, if they lead to better code going into the kernel, are
|
||||||
|
welcome and worthwhile.
|
||||||
|
|
||||||
|
|
|
@ -0,0 +1,74 @@
|
||||||
|
8: FOR MORE INFORMATION
|
||||||
|
|
||||||
|
There are numerous sources of information on Linux kernel development and
|
||||||
|
related topics. First among those will always be the Documentation
|
||||||
|
directory found in the kernel source distribution. The top-level HOWTO
|
||||||
|
file is an important starting point; SubmittingPatches and
|
||||||
|
SubmittingDrivers are also something which all kernel developers should
|
||||||
|
read. Many internal kernel APIs are documented using the kerneldoc
|
||||||
|
mechanism; "make htmldocs" or "make pdfdocs" can be used to generate those
|
||||||
|
documents in HTML or PDF format (though the version of TeX shipped by some
|
||||||
|
distributions runs into internal limits and fails to process the documents
|
||||||
|
properly).
|
||||||
|
|
||||||
|
Various web sites discuss kernel development at all levels of detail. Your
|
||||||
|
author would like to humbly suggest http://lwn.net/ as a source;
|
||||||
|
information on many specific kernel topics can be found via the LWN kernel
|
||||||
|
index at:
|
||||||
|
|
||||||
|
http://lwn.net/Kernel/Index/
|
||||||
|
|
||||||
|
Beyond that, a valuable resource for kernel developers is:
|
||||||
|
|
||||||
|
http://kernelnewbies.org/
|
||||||
|
|
||||||
|
Information about the linux-next tree gathers at:
|
||||||
|
|
||||||
|
http://linux.f-seidel.de/linux-next/pmwiki/
|
||||||
|
|
||||||
|
And, of course, one should not forget http://kernel.org/, the definitive
|
||||||
|
location for kernel release information.
|
||||||
|
|
||||||
|
There are a number of books on kernel development:
|
||||||
|
|
||||||
|
Linux Device Drivers, 3rd Edition (Jonathan Corbet, Alessandro
|
||||||
|
Rubini, and Greg Kroah-Hartman). Online at
|
||||||
|
http://lwn.net/Kernel/LDD3/.
|
||||||
|
|
||||||
|
Linux Kernel Development (Robert Love).
|
||||||
|
|
||||||
|
Understanding the Linux Kernel (Daniel Bovet and Marco Cesati).
|
||||||
|
|
||||||
|
All of these books suffer from a common fault, though: they tend to be
|
||||||
|
somewhat obsolete by the time they hit the shelves, and they have been on
|
||||||
|
the shelves for a while now. Still, there is quite a bit of good
|
||||||
|
information to be found there.
|
||||||
|
|
||||||
|
Documentation for git can be found at:
|
||||||
|
|
||||||
|
http://www.kernel.org/pub/software/scm/git/docs/
|
||||||
|
|
||||||
|
http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
|
||||||
|
|
||||||
|
|
||||||
|
9: CONCLUSION
|
||||||
|
|
||||||
|
Congratulations to anybody who has made it through this long-winded
|
||||||
|
document. Hopefully it has provided a helpful understanding of how the
|
||||||
|
Linux kernel is developed and how you can participate in that process.
|
||||||
|
|
||||||
|
In the end, it's the participation that matters. Any open source software
|
||||||
|
project is no more than the sum of what its contributors put into it. The
|
||||||
|
Linux kernel has progressed as quickly and as well as it has because it has
|
||||||
|
been helped by an impressively large group of developers, all of whom are
|
||||||
|
working to make it better. The kernel is a premier example of what can be
|
||||||
|
done when thousands of people work together toward a common goal.
|
||||||
|
|
||||||
|
The kernel can always benefit from a larger developer base, though. There
|
||||||
|
is always more work to do. But, just as importantly, most other
|
||||||
|
participants in the Linux ecosystem can benefit through contributing to the
|
||||||
|
kernel. Getting code into the mainline is the key to higher code quality,
|
||||||
|
lower maintenance and distribution costs, a higher level of influence over
|
||||||
|
the direction of kernel development, and more. It is a situation where
|
||||||
|
everybody involved wins. Fire up your editor and come join us; you will be
|
||||||
|
more than welcome.
|
|
@ -2571,6 +2571,9 @@ Your cooperation is appreciated.
|
||||||
160 = /dev/usb/legousbtower0 1st USB Legotower device
|
160 = /dev/usb/legousbtower0 1st USB Legotower device
|
||||||
...
|
...
|
||||||
175 = /dev/usb/legousbtower15 16th USB Legotower device
|
175 = /dev/usb/legousbtower15 16th USB Legotower device
|
||||||
|
176 = /dev/usb/usbtmc1 First USB TMC device
|
||||||
|
...
|
||||||
|
192 = /dev/usb/usbtmc16 16th USB TMC device
|
||||||
240 = /dev/usb/dabusb0 First daubusb device
|
240 = /dev/usb/dabusb0 First daubusb device
|
||||||
...
|
...
|
||||||
243 = /dev/usb/dabusb3 Fourth dabusb device
|
243 = /dev/usb/dabusb3 Fourth dabusb device
|
||||||
|
|
|
@ -2,11 +2,13 @@
|
||||||
*.aux
|
*.aux
|
||||||
*.bin
|
*.bin
|
||||||
*.cpio
|
*.cpio
|
||||||
*.css
|
*.csp
|
||||||
|
*.dsp
|
||||||
*.dvi
|
*.dvi
|
||||||
|
*.elf
|
||||||
*.eps
|
*.eps
|
||||||
*.fw.gen.S
|
|
||||||
*.fw
|
*.fw
|
||||||
|
*.gen.S
|
||||||
*.gif
|
*.gif
|
||||||
*.grep
|
*.grep
|
||||||
*.grp
|
*.grp
|
||||||
|
@ -30,6 +32,7 @@
|
||||||
*.s
|
*.s
|
||||||
*.sgml
|
*.sgml
|
||||||
*.so
|
*.so
|
||||||
|
*.so.dbg
|
||||||
*.symtypes
|
*.symtypes
|
||||||
*.tab.c
|
*.tab.c
|
||||||
*.tab.h
|
*.tab.h
|
||||||
|
@ -38,24 +41,17 @@
|
||||||
*.xml
|
*.xml
|
||||||
*_MODULES
|
*_MODULES
|
||||||
*_vga16.c
|
*_vga16.c
|
||||||
*cscope*
|
|
||||||
*~
|
*~
|
||||||
*.9
|
*.9
|
||||||
*.9.gz
|
*.9.gz
|
||||||
.*
|
.*
|
||||||
.cscope
|
|
||||||
.gitignore
|
|
||||||
.mailmap
|
|
||||||
.mm
|
.mm
|
||||||
53c700_d.h
|
53c700_d.h
|
||||||
53c8xx_d.h*
|
|
||||||
COPYING
|
|
||||||
CREDITS
|
|
||||||
CVS
|
CVS
|
||||||
ChangeSet
|
ChangeSet
|
||||||
Image
|
Image
|
||||||
Kerntypes
|
Kerntypes
|
||||||
MODS.txt
|
Module.markers
|
||||||
Module.symvers
|
Module.symvers
|
||||||
PENDING
|
PENDING
|
||||||
SCCS
|
SCCS
|
||||||
|
@ -73,7 +69,9 @@ autoconf.h*
|
||||||
bbootsect
|
bbootsect
|
||||||
bin2c
|
bin2c
|
||||||
binkernel.spec
|
binkernel.spec
|
||||||
|
binoffset
|
||||||
bootsect
|
bootsect
|
||||||
|
bounds.h
|
||||||
bsetup
|
bsetup
|
||||||
btfixupprep
|
btfixupprep
|
||||||
build
|
build
|
||||||
|
@ -89,39 +87,36 @@ config_data.h*
|
||||||
config_data.gz*
|
config_data.gz*
|
||||||
conmakehash
|
conmakehash
|
||||||
consolemap_deftbl.c*
|
consolemap_deftbl.c*
|
||||||
|
cpustr.h
|
||||||
crc32table.h*
|
crc32table.h*
|
||||||
cscope.*
|
cscope.*
|
||||||
defkeymap.c*
|
defkeymap.c
|
||||||
devlist.h*
|
devlist.h*
|
||||||
docproc
|
docproc
|
||||||
dummy_sym.c*
|
|
||||||
elf2ecoff
|
elf2ecoff
|
||||||
elfconfig.h*
|
elfconfig.h*
|
||||||
filelist
|
|
||||||
fixdep
|
fixdep
|
||||||
fore200e_mkfirm
|
fore200e_mkfirm
|
||||||
fore200e_pca_fw.c*
|
fore200e_pca_fw.c*
|
||||||
gconf
|
gconf
|
||||||
gen-devlist
|
gen-devlist
|
||||||
gen-kdb_cmds.c*
|
|
||||||
gen_crc32table
|
gen_crc32table
|
||||||
gen_init_cpio
|
gen_init_cpio
|
||||||
genksyms
|
genksyms
|
||||||
gentbl
|
|
||||||
*_gray256.c
|
*_gray256.c
|
||||||
|
ihex2fw
|
||||||
ikconfig.h*
|
ikconfig.h*
|
||||||
initramfs_data.cpio
|
initramfs_data.cpio
|
||||||
initramfs_data.cpio.gz
|
initramfs_data.cpio.gz
|
||||||
initramfs_list
|
initramfs_list
|
||||||
kallsyms
|
kallsyms
|
||||||
kconfig
|
kconfig
|
||||||
kconfig.tk
|
keywords.c
|
||||||
keywords.c*
|
|
||||||
ksym.c*
|
ksym.c*
|
||||||
ksym.h*
|
ksym.h*
|
||||||
kxgettext
|
kxgettext
|
||||||
lkc_defs.h
|
lkc_defs.h
|
||||||
lex.c*
|
lex.c
|
||||||
lex.*.c
|
lex.*.c
|
||||||
logo_*.c
|
logo_*.c
|
||||||
logo_*_clut224.c
|
logo_*_clut224.c
|
||||||
|
@ -130,7 +125,6 @@ lxdialog
|
||||||
mach-types
|
mach-types
|
||||||
mach-types.h
|
mach-types.h
|
||||||
machtypes.h
|
machtypes.h
|
||||||
make_times_h
|
|
||||||
map
|
map
|
||||||
maui_boot.h
|
maui_boot.h
|
||||||
mconf
|
mconf
|
||||||
|
@ -138,6 +132,7 @@ miboot*
|
||||||
mk_elfconfig
|
mk_elfconfig
|
||||||
mkboot
|
mkboot
|
||||||
mkbugboot
|
mkbugboot
|
||||||
|
mkcpustr
|
||||||
mkdep
|
mkdep
|
||||||
mkprep
|
mkprep
|
||||||
mktables
|
mktables
|
||||||
|
@ -145,11 +140,12 @@ mktree
|
||||||
modpost
|
modpost
|
||||||
modules.order
|
modules.order
|
||||||
modversions.h*
|
modversions.h*
|
||||||
|
ncscope.*
|
||||||
offset.h
|
offset.h
|
||||||
offsets.h
|
offsets.h
|
||||||
oui.c*
|
oui.c*
|
||||||
parse.c*
|
parse.c
|
||||||
parse.h*
|
parse.h
|
||||||
patches*
|
patches*
|
||||||
pca200e.bin
|
pca200e.bin
|
||||||
pca200e_ecd.bin2
|
pca200e_ecd.bin2
|
||||||
|
@ -157,7 +153,7 @@ piggy.gz
|
||||||
piggyback
|
piggyback
|
||||||
pnmtologo
|
pnmtologo
|
||||||
ppc_defs.h*
|
ppc_defs.h*
|
||||||
promcon_tbl.c*
|
promcon_tbl.c
|
||||||
pss_boot.h
|
pss_boot.h
|
||||||
qconf
|
qconf
|
||||||
raid6altivec*.c
|
raid6altivec*.c
|
||||||
|
@ -168,27 +164,38 @@ series
|
||||||
setup
|
setup
|
||||||
setup.bin
|
setup.bin
|
||||||
setup.elf
|
setup.elf
|
||||||
sim710_d.h*
|
|
||||||
sImage
|
sImage
|
||||||
sm_tbl*
|
sm_tbl*
|
||||||
split-include
|
split-include
|
||||||
|
syscalltab.h
|
||||||
tags
|
tags
|
||||||
tftpboot.img
|
tftpboot.img
|
||||||
timeconst.h
|
timeconst.h
|
||||||
times.h*
|
times.h*
|
||||||
tkparse
|
|
||||||
trix_boot.h
|
trix_boot.h
|
||||||
utsrelease.h*
|
utsrelease.h*
|
||||||
|
vdso-syms.lds
|
||||||
vdso.lds
|
vdso.lds
|
||||||
|
vdso32-int80-syms.lds
|
||||||
|
vdso32-syms.lds
|
||||||
|
vdso32-syscall-syms.lds
|
||||||
|
vdso32-sysenter-syms.lds
|
||||||
|
vdso32.lds
|
||||||
|
vdso32.so.dbg
|
||||||
|
vdso64.lds
|
||||||
|
vdso64.so.dbg
|
||||||
version.h*
|
version.h*
|
||||||
vmlinux
|
vmlinux
|
||||||
vmlinux-*
|
vmlinux-*
|
||||||
vmlinux.aout
|
vmlinux.aout
|
||||||
vmlinux*.lds*
|
vmlinux.lds
|
||||||
vmlinux*.scr
|
|
||||||
vsyscall.lds
|
vsyscall.lds
|
||||||
|
vsyscall_32.lds
|
||||||
wanxlfw.inc
|
wanxlfw.inc
|
||||||
uImage
|
uImage
|
||||||
unifdef
|
unifdef
|
||||||
|
wakeup.bin
|
||||||
|
wakeup.elf
|
||||||
|
wakeup.lds
|
||||||
zImage*
|
zImage*
|
||||||
zconf.hash.c
|
zconf.hash.c
|
||||||
|
|
|
@ -14,6 +14,7 @@ graphics devices. These would include:
|
||||||
Intel 915GM
|
Intel 915GM
|
||||||
Intel 945G
|
Intel 945G
|
||||||
Intel 945GM
|
Intel 945GM
|
||||||
|
Intel 945GME
|
||||||
Intel 965G
|
Intel 965G
|
||||||
Intel 965GM
|
Intel 965GM
|
||||||
|
|
||||||
|
|
|
@ -52,7 +52,7 @@ are either given on the kernel command line or as module parameters, e.g.:
|
||||||
|
|
||||||
video=uvesafb:1024x768-32,mtrr:3,ywrap (compiled into the kernel)
|
video=uvesafb:1024x768-32,mtrr:3,ywrap (compiled into the kernel)
|
||||||
|
|
||||||
# modprobe uvesafb mode=1024x768-32 mtrr=3 scroll=ywrap (module)
|
# modprobe uvesafb mode_option=1024x768-32 mtrr=3 scroll=ywrap (module)
|
||||||
|
|
||||||
Accepted options:
|
Accepted options:
|
||||||
|
|
||||||
|
@ -105,7 +105,7 @@ vtotal:n
|
||||||
<mode> The mode you want to set, in the standard modedb format. Refer to
|
<mode> The mode you want to set, in the standard modedb format. Refer to
|
||||||
modedb.txt for a detailed description. When uvesafb is compiled as
|
modedb.txt for a detailed description. When uvesafb is compiled as
|
||||||
a module, the mode string should be provided as a value of the
|
a module, the mode string should be provided as a value of the
|
||||||
'mode' option.
|
'mode_option' option.
|
||||||
|
|
||||||
vbemode:x
|
vbemode:x
|
||||||
Force the use of VBE mode x. The mode will only be set if it's
|
Force the use of VBE mode x. The mode will only be set if it's
|
||||||
|
|
|
@ -0,0 +1,870 @@
|
||||||
|
#
|
||||||
|
#
|
||||||
|
# These data are based on the CRTC parameters in
|
||||||
|
#
|
||||||
|
# VIA Integration Graphics Chip
|
||||||
|
# (C) 2004 VIA Technologies Inc.
|
||||||
|
#
|
||||||
|
|
||||||
|
#
|
||||||
|
# 640x480, 60 Hz, Non-Interlaced (25.175 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 640 480
|
||||||
|
# Scan Frequency 31.469 kHz 59.94 Hz
|
||||||
|
# Sync Width 3.813 us 0.064 ms
|
||||||
|
# 12 chars 2 lines
|
||||||
|
# Front Porch 0.636 us 0.318 ms
|
||||||
|
# 2 chars 10 lines
|
||||||
|
# Back Porch 1.907 us 1.048 ms
|
||||||
|
# 6 chars 33 lines
|
||||||
|
# Active Time 25.422 us 15.253 ms
|
||||||
|
# 80 chars 480 lines
|
||||||
|
# Blank Time 6.356 us 1.430 ms
|
||||||
|
# 20 chars 45 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
|
||||||
|
mode "640x480-60"
|
||||||
|
# D: 25.175 MHz, H: 31.469 kHz, V: 59.94 Hz
|
||||||
|
geometry 640 480 640 480 32
|
||||||
|
timings 39722 48 16 33 10 96 2 endmode mode "480x640-60"
|
||||||
|
# D: 24.823 MHz, H: 39.780 kHz, V: 60.00 Hz
|
||||||
|
geometry 480 640 480 640 32 timings 39722 72 24 19 1 48 3 endmode
|
||||||
|
#
|
||||||
|
# 640x480, 75 Hz, Non-Interlaced (31.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 640 480
|
||||||
|
# Scan Frequency 37.500 kHz 75.00 Hz
|
||||||
|
# Sync Width 2.032 us 0.080 ms
|
||||||
|
# 8 chars 3 lines
|
||||||
|
# Front Porch 0.508 us 0.027 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.810 us 0.427 ms
|
||||||
|
# 15 chars 16 lines
|
||||||
|
# Active Time 20.317 us 12.800 ms
|
||||||
|
# 80 chars 480 lines
|
||||||
|
# Blank Time 6.349 us 0.533 ms
|
||||||
|
# 25 chars 20 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "640x480-75"
|
||||||
|
# D: 31.50 MHz, H: 37.500 kHz, V: 75.00 Hz
|
||||||
|
geometry 640 480 640 480 32 timings 31747 120 16 16 1 64 3 endmode
|
||||||
|
#
|
||||||
|
# 640x480, 85 Hz, Non-Interlaced (36.000 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 640 480
|
||||||
|
# Scan Frequency 43.269 kHz 85.00 Hz
|
||||||
|
# Sync Width 1.556 us 0.069 ms
|
||||||
|
# 7 chars 3 lines
|
||||||
|
# Front Porch 1.556 us 0.023 ms
|
||||||
|
# 7 chars 1 lines
|
||||||
|
# Back Porch 2.222 us 0.578 ms
|
||||||
|
# 10 chars 25 lines
|
||||||
|
# Active Time 17.778 us 11.093 ms
|
||||||
|
# 80 chars 480 lines
|
||||||
|
# Blank Time 5.333 us 0.670 ms
|
||||||
|
# 24 chars 29 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "640x480-85"
|
||||||
|
# D: 36.000 MHz, H: 43.269 kHz, V: 85.00 Hz
|
||||||
|
geometry 640 480 640 480 32 timings 27777 80 56 25 1 56 3 endmode
|
||||||
|
#
|
||||||
|
# 640x480, 100 Hz, Non-Interlaced (43.163 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 640 480
|
||||||
|
# Scan Frequency 50.900 kHz 100.00 Hz
|
||||||
|
# Sync Width 1.483 us 0.058 ms
|
||||||
|
# 8 chars 3 lines
|
||||||
|
# Front Porch 0.927 us 0.019 ms
|
||||||
|
# 5 chars 1 lines
|
||||||
|
# Back Porch 2.409 us 0.475 ms
|
||||||
|
# 13 chars 25 lines
|
||||||
|
# Active Time 14.827 us 9.430 ms
|
||||||
|
# 80 chars 480 lines
|
||||||
|
# Blank Time 4.819 us 0.570 ms
|
||||||
|
# 26 chars 29 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "640x480-100"
|
||||||
|
# D: 43.163 MHz, H: 50.900 kHz, V: 100.00 Hz
|
||||||
|
geometry 640 480 640 480 32 timings 23168 104 40 25 1 64 3 endmode
|
||||||
|
#
|
||||||
|
# 640x480, 120 Hz, Non-Interlaced (52.406 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 640 480
|
||||||
|
# Scan Frequency 61.800 kHz 120.00 Hz
|
||||||
|
# Sync Width 1.221 us 0.048 ms
|
||||||
|
# 8 chars 3 lines
|
||||||
|
# Front Porch 0.763 us 0.016 ms
|
||||||
|
# 5 chars 1 lines
|
||||||
|
# Back Porch 1.984 us 0.496 ms
|
||||||
|
# 13 chars 31 lines
|
||||||
|
# Active Time 12.212 us 7.767 ms
|
||||||
|
# 80 chars 480 lines
|
||||||
|
# Blank Time 3.969 us 0.566 ms
|
||||||
|
# 26 chars 35 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "640x480-120"
|
||||||
|
# D: 52.406 MHz, H: 61.800 kHz, V: 120.00 Hz
|
||||||
|
geometry 640 480 640 480 32 timings 19081 104 40 31 1 64 3 endmode
|
||||||
|
#
|
||||||
|
# 720x480, 60 Hz, Non-Interlaced (26.880 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 720 480
|
||||||
|
# Scan Frequency 30.000 kHz 60.241 Hz
|
||||||
|
# Sync Width 2.679 us 0.099 ms
|
||||||
|
# 9 chars 3 lines
|
||||||
|
# Front Porch 0.595 us 0.033 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.274 us 0.462 ms
|
||||||
|
# 11 chars 14 lines
|
||||||
|
# Active Time 26.786 us 16.000 ms
|
||||||
|
# 90 chars 480 lines
|
||||||
|
# Blank Time 6.548 us 0.600 ms
|
||||||
|
# 22 chars 18 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "720x480-60"
|
||||||
|
# D: 26.880 MHz, H: 30.000 kHz, V: 60.24 Hz
|
||||||
|
geometry 720 480 720 480 32 timings 37202 88 16 14 1 72 3 endmode
|
||||||
|
#
|
||||||
|
# 800x480, 60 Hz, Non-Interlaced (29.581 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 480
|
||||||
|
# Scan Frequency 29.892 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.704 us 100.604 us
|
||||||
|
# 10 chars 3 lines
|
||||||
|
# Front Porch 0.541 us 33.535 us
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.245 us 435.949 us
|
||||||
|
# 12 chars 13 lines
|
||||||
|
# Active Time 27.044 us 16.097 ms
|
||||||
|
# 100 chars 480 lines
|
||||||
|
# Blank Time 6.491 us 0.570 ms
|
||||||
|
# 24 chars 17 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x480-60"
|
||||||
|
# D: 29.500 MHz, H: 29.738 kHz, V: 60.00 Hz
|
||||||
|
geometry 800 480 800 480 32 timings 33805 96 24 10 3 72 7 endmode
|
||||||
|
#
|
||||||
|
# 720x576, 60 Hz, Non-Interlaced (32.668 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 720 576
|
||||||
|
# Scan Frequency 35.820 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.204 us 0.083 ms
|
||||||
|
# 9 chars 3 lines
|
||||||
|
# Front Porch 0.735 us 0.027 ms
|
||||||
|
# 3 chars 1 lines
|
||||||
|
# Back Porch 2.939 us 0.459 ms
|
||||||
|
# 12 chars 17 lines
|
||||||
|
# Active Time 22.040 us 16.080 ms
|
||||||
|
# 90 chars 476 lines
|
||||||
|
# Blank Time 5.877 us 0.586 ms
|
||||||
|
# 24 chars 21 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "720x576-60"
|
||||||
|
# D: 32.668 MHz, H: 35.820 kHz, V: 60.00 Hz
|
||||||
|
geometry 720 576 720 576 32 timings 30611 96 24 17 1 72 3 endmode
|
||||||
|
#
|
||||||
|
# 800x600, 60 Hz, Non-Interlaced (40.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 600
|
||||||
|
# Scan Frequency 37.879 kHz 60.32 Hz
|
||||||
|
# Sync Width 3.200 us 0.106 ms
|
||||||
|
# 16 chars 4 lines
|
||||||
|
# Front Porch 1.000 us 0.026 ms
|
||||||
|
# 5 chars 1 lines
|
||||||
|
# Back Porch 2.200 us 0.607 ms
|
||||||
|
# 11 chars 23 lines
|
||||||
|
# Active Time 20.000 us 15.840 ms
|
||||||
|
# 100 chars 600 lines
|
||||||
|
# Blank Time 6.400 us 0.739 ms
|
||||||
|
# 32 chars 28 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x600-60"
|
||||||
|
# D: 40.00 MHz, H: 37.879 kHz, V: 60.32 Hz
|
||||||
|
geometry 800 600 800 600 32
|
||||||
|
timings 25000 88 40 23 1 128 4 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 800x600, 75 Hz, Non-Interlaced (49.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 600
|
||||||
|
# Scan Frequency 46.875 kHz 75.00 Hz
|
||||||
|
# Sync Width 1.616 us 0.064 ms
|
||||||
|
# 10 chars 3 lines
|
||||||
|
# Front Porch 0.323 us 0.021 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.232 us 0.448 ms
|
||||||
|
# 20 chars 21 lines
|
||||||
|
# Active Time 16.162 us 12.800 ms
|
||||||
|
# 100 chars 600 lines
|
||||||
|
# Blank Time 5.172 us 0.533 ms
|
||||||
|
# 32 chars 25 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x600-75"
|
||||||
|
# D: 49.50 MHz, H: 46.875 kHz, V: 75.00 Hz
|
||||||
|
geometry 800 600 800 600 32
|
||||||
|
timings 20203 160 16 21 1 80 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 800x600, 85 Hz, Non-Interlaced (56.25 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 600
|
||||||
|
# Scan Frequency 53.674 kHz 85.061 Hz
|
||||||
|
# Sync Width 1.138 us 0.056 ms
|
||||||
|
# 8 chars 3 lines
|
||||||
|
# Front Porch 0.569 us 0.019 ms
|
||||||
|
# 4 chars 1 lines
|
||||||
|
# Back Porch 2.702 us 0.503 ms
|
||||||
|
# 19 chars 27 lines
|
||||||
|
# Active Time 14.222 us 11.179 ms
|
||||||
|
# 100 chars 600 lines
|
||||||
|
# Blank Time 4.409 us 0.578 ms
|
||||||
|
# 31 chars 31 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x600-85"
|
||||||
|
# D: 56.25 MHz, H: 53.674 kHz, V: 85.061 Hz
|
||||||
|
geometry 800 600 800 600 32
|
||||||
|
timings 17777 152 32 27 1 64 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 800x600, 100 Hz, Non-Interlaced (67.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 600
|
||||||
|
# Scan Frequency 62.500 kHz 100.00 Hz
|
||||||
|
# Sync Width 0.948 us 0.064 ms
|
||||||
|
# 8 chars 4 lines
|
||||||
|
# Front Porch 0.000 us 0.112 ms
|
||||||
|
# 0 chars 7 lines
|
||||||
|
# Back Porch 3.200 us 0.224 ms
|
||||||
|
# 27 chars 14 lines
|
||||||
|
# Active Time 11.852 us 9.600 ms
|
||||||
|
# 100 chars 600 lines
|
||||||
|
# Blank Time 4.148 us 0.400 ms
|
||||||
|
# 35 chars 25 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x600-100"
|
||||||
|
# D: 67.50 MHz, H: 62.500 kHz, V: 100.00 Hz
|
||||||
|
geometry 800 600 800 600 32
|
||||||
|
timings 14667 216 0 14 7 64 4 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 800x600, 120 Hz, Non-Interlaced (83.950 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 800 600
|
||||||
|
# Scan Frequency 77.160 kHz 120.00 Hz
|
||||||
|
# Sync Width 1.048 us 0.039 ms
|
||||||
|
# 11 chars 3 lines
|
||||||
|
# Front Porch 0.667 us 0.013 ms
|
||||||
|
# 7 chars 1 lines
|
||||||
|
# Back Porch 1.715 us 0.507 ms
|
||||||
|
# 18 chars 39 lines
|
||||||
|
# Active Time 9.529 us 7.776 ms
|
||||||
|
# 100 chars 600 lines
|
||||||
|
# Blank Time 3.431 us 0.557 ms
|
||||||
|
# 36 chars 43 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "800x600-120"
|
||||||
|
# D: 83.950 MHz, H: 77.160 kHz, V: 120.00 Hz
|
||||||
|
geometry 800 600 800 600 32
|
||||||
|
timings 11912 144 56 39 1 88 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 848x480, 60 Hz, Non-Interlaced (31.490 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 848 480
|
||||||
|
# Scan Frequency 29.820 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.795 us 0.099 ms
|
||||||
|
# 11 chars 3 lines
|
||||||
|
# Front Porch 0.508 us 0.033 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.303 us 0.429 ms
|
||||||
|
# 13 chars 13 lines
|
||||||
|
# Active Time 26.929 us 16.097 ms
|
||||||
|
# 106 chars 480 lines
|
||||||
|
# Blank Time 6.605 us 0.570 ms
|
||||||
|
# 26 chars 17 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "848x480-60"
|
||||||
|
# D: 31.500 MHz, H: 29.830 kHz, V: 60.00 Hz
|
||||||
|
geometry 848 480 848 480 32
|
||||||
|
timings 31746 104 24 12 3 80 5 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 856x480, 60 Hz, Non-Interlaced (31.728 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 856 480
|
||||||
|
# Scan Frequency 29.820 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.774 us 0.099 ms
|
||||||
|
# 11 chars 3 lines
|
||||||
|
# Front Porch 0.504 us 0.033 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 3.728 us 0.429 ms
|
||||||
|
# 13 chars 13 lines
|
||||||
|
# Active Time 26.979 us 16.097 ms
|
||||||
|
# 107 chars 480 lines
|
||||||
|
# Blank Time 6.556 us 0.570 ms
|
||||||
|
# 26 chars 17 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "856x480-60"
|
||||||
|
# D: 31.728 MHz, H: 29.820 kHz, V: 60.00 Hz
|
||||||
|
geometry 856 480 856 480 32
|
||||||
|
timings 31518 104 16 13 1 88 3
|
||||||
|
hsync high vsync high endmode mode "960x600-60"
|
||||||
|
# D: 45.250 MHz, H: 37.212 kHz, V: 60.00 Hz
|
||||||
|
geometry 960 600 960 600 32 timings 22099 128 32 15 3 96 6 endmode
|
||||||
|
#
|
||||||
|
# 1000x600, 60 Hz, Non-Interlaced (48.068 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1000 600
|
||||||
|
# Scan Frequency 37.320 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.164 us 0.080 ms
|
||||||
|
# 13 chars 3 lines
|
||||||
|
# Front Porch 0.832 us 0.027 ms
|
||||||
|
# 5 chars 1 lines
|
||||||
|
# Back Porch 2.996 us 0.483 ms
|
||||||
|
# 18 chars 18 lines
|
||||||
|
# Active Time 20.804 us 16.077 ms
|
||||||
|
# 125 chars 600 lines
|
||||||
|
# Blank Time 5.991 us 0.589 ms
|
||||||
|
# 36 chars 22 lines
|
||||||
|
# Polarity negative positive
|
||||||
|
#
|
||||||
|
mode "1000x600-60"
|
||||||
|
# D: 48.068 MHz, H: 37.320 kHz, V: 60.00 Hz
|
||||||
|
geometry 1000 600 1000 600 32
|
||||||
|
timings 20834 144 40 18 1 104 3 endmode mode "1024x576-60"
|
||||||
|
# D: 46.996 MHz, H: 35.820 kHz, V: 60.00 Hz
|
||||||
|
geometry 1024 576 1024 576 32
|
||||||
|
timings 21278 144 40 17 1 104 3 endmode mode "1024x600-60"
|
||||||
|
# D: 48.964 MHz, H: 37.320 kHz, V: 60.00 Hz
|
||||||
|
geometry 1024 600 1024 600 32
|
||||||
|
timings 20461 144 40 18 1 104 3 endmode mode "1088x612-60"
|
||||||
|
# D: 52.952 MHz, H: 38.040 kHz, V: 60.00 Hz
|
||||||
|
geometry 1088 612 1088 612 32 timings 18877 152 48 16 3 104 5 endmode
|
||||||
|
#
|
||||||
|
# 1024x512, 60 Hz, Non-Interlaced (41.291 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 512
|
||||||
|
# Scan Frequency 31.860 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.519 us 0.094 ms
|
||||||
|
# 13 chars 3 lines
|
||||||
|
# Front Porch 0.775 us 0.031 ms
|
||||||
|
# 4 chars 1 lines
|
||||||
|
# Back Porch 3.294 us 0.465 ms
|
||||||
|
# 17 chars 15 lines
|
||||||
|
# Active Time 24.800 us 16.070 ms
|
||||||
|
# 128 chars 512 lines
|
||||||
|
# Blank Time 6.587 us 0.596 ms
|
||||||
|
# 34 chars 19 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1024x512-60"
|
||||||
|
# D: 41.291 MHz, H: 31.860 kHz, V: 60.00 Hz
|
||||||
|
geometry 1024 512 1024 512 32
|
||||||
|
timings 24218 126 32 15 1 104 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1024x600, 60 Hz, Non-Interlaced (48.875 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 768
|
||||||
|
# Scan Frequency 37.252 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.128 us 80.532us
|
||||||
|
# 13 chars 3 lines
|
||||||
|
# Front Porch 0.818 us 26.844 us
|
||||||
|
# 5 chars 1 lines
|
||||||
|
# Back Porch 2.946 us 483.192 us
|
||||||
|
# 18 chars 18 lines
|
||||||
|
# Active Time 20.951 us 16.697 ms
|
||||||
|
# 128 chars 622 lines
|
||||||
|
# Blank Time 5.893 us 0.591 ms
|
||||||
|
# 36 chars 22 lines
|
||||||
|
# Polarity negative positive
|
||||||
|
#
|
||||||
|
#mode "1024x600-60"
|
||||||
|
# # D: 48.875 MHz, H: 37.252 kHz, V: 60.00 Hz
|
||||||
|
# geometry 1024 600 1024 600 32
|
||||||
|
# timings 20460 144 40 18 1 104 3
|
||||||
|
# endmode
|
||||||
|
#
|
||||||
|
# 1024x768, 60 Hz, Non-Interlaced (65.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 768
|
||||||
|
# Scan Frequency 48.363 kHz 60.00 Hz
|
||||||
|
# Sync Width 2.092 us 0.124 ms
|
||||||
|
# 17 chars 6 lines
|
||||||
|
# Front Porch 0.369 us 0.062 ms
|
||||||
|
# 3 chars 3 lines
|
||||||
|
# Back Porch 2.462 us 0.601 ms
|
||||||
|
# 20 chars 29 lines
|
||||||
|
# Active Time 15.754 us 15.880 ms
|
||||||
|
# 128 chars 768 lines
|
||||||
|
# Blank Time 4.923 us 0.786 ms
|
||||||
|
# 40 chars 38 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "1024x768-60"
|
||||||
|
# D: 65.00 MHz, H: 48.363 kHz, V: 60.00 Hz
|
||||||
|
geometry 1024 768 1024 768 32 timings 15385 160 24 29 3 136 6 endmode
|
||||||
|
#
|
||||||
|
# 1024x768, 75 Hz, Non-Interlaced (78.75 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 768
|
||||||
|
# Scan Frequency 60.023 kHz 75.03 Hz
|
||||||
|
# Sync Width 1.219 us 0.050 ms
|
||||||
|
# 12 chars 3 lines
|
||||||
|
# Front Porch 0.203 us 0.017 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 2.235 us 0.466 ms
|
||||||
|
# 22 chars 28 lines
|
||||||
|
# Active Time 13.003 us 12.795 ms
|
||||||
|
# 128 chars 768 lines
|
||||||
|
# Blank Time 3.657 us 0.533 ms
|
||||||
|
# 36 chars 32 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1024x768-75"
|
||||||
|
# D: 78.75 MHz, H: 60.023 kHz, V: 75.03 Hz
|
||||||
|
geometry 1024 768 1024 768 32
|
||||||
|
timings 12699 176 16 28 1 96 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1024x768, 85 Hz, Non-Interlaced (94.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 768
|
||||||
|
# Scan Frequency 68.677 kHz 85.00 Hz
|
||||||
|
# Sync Width 1.016 us 0.044 ms
|
||||||
|
# 12 chars 3 lines
|
||||||
|
# Front Porch 0.508 us 0.015 ms
|
||||||
|
# 6 chars 1 lines
|
||||||
|
# Back Porch 2.201 us 0.524 ms
|
||||||
|
# 26 chars 36 lines
|
||||||
|
# Active Time 10.836 us 11.183 ms
|
||||||
|
# 128 chars 768 lines
|
||||||
|
# Blank Time 3.725 us 0.582 ms
|
||||||
|
# 44 chars 40 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1024x768-85"
|
||||||
|
# D: 94.50 MHz, H: 68.677 kHz, V: 85.00 Hz
|
||||||
|
geometry 1024 768 1024 768 32
|
||||||
|
timings 10582 208 48 36 1 96 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1024x768, 100 Hz, Non-Interlaced (110.0 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1024 768
|
||||||
|
# Scan Frequency 79.023 kHz 99.78 Hz
|
||||||
|
# Sync Width 0.800 us 0.101 ms
|
||||||
|
# 11 chars 8 lines
|
||||||
|
# Front Porch 0.000 us 0.000 ms
|
||||||
|
# 0 chars 0 lines
|
||||||
|
# Back Porch 2.545 us 0.202 ms
|
||||||
|
# 35 chars 16 lines
|
||||||
|
# Active Time 9.309 us 9.719 ms
|
||||||
|
# 128 chars 768 lines
|
||||||
|
# Blank Time 3.345 us 0.304 ms
|
||||||
|
# 46 chars 24 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "1024x768-100"
|
||||||
|
# D: 113.3 MHz, H: 79.023 kHz, V: 99.78 Hz
|
||||||
|
geometry 1024 768 1024 768 32
|
||||||
|
timings 8825 280 0 16 0 88 8 endmode mode "1152x720-60"
|
||||||
|
# D: 66.750 MHz, H: 44.859 kHz, V: 60.00 Hz
|
||||||
|
geometry 1152 720 1152 720 32 timings 14981 168 56 19 3 112 6 endmode
|
||||||
|
#
|
||||||
|
# 1152x864, 75 Hz, Non-Interlaced (110.0 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1152 864
|
||||||
|
# Scan Frequency 75.137 kHz 74.99 Hz
|
||||||
|
# Sync Width 1.309 us 0.106 ms
|
||||||
|
# 18 chars 8 lines
|
||||||
|
# Front Porch 0.245 us 0.599 ms
|
||||||
|
# 3 chars 45 lines
|
||||||
|
# Back Porch 1.282 us 1.132 ms
|
||||||
|
# 18 chars 85 lines
|
||||||
|
# Active Time 10.473 us 11.499 ms
|
||||||
|
# 144 chars 864 lines
|
||||||
|
# Blank Time 2.836 us 1.837 ms
|
||||||
|
# 39 chars 138 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1152x864-75"
|
||||||
|
# D: 110.0 MHz, H: 75.137 kHz, V: 74.99 Hz
|
||||||
|
geometry 1152 864 1152 864 32
|
||||||
|
timings 9259 144 24 85 45 144 8
|
||||||
|
hsync high vsync high endmode mode "1200x720-60"
|
||||||
|
# D: 70.184 MHz, H: 44.760 kHz, V: 60.00 Hz
|
||||||
|
geometry 1200 720 1200 720 32
|
||||||
|
timings 14253 184 28 22 1 128 3 endmode mode "1280x600-60"
|
||||||
|
# D: 61.503 MHz, H: 37.320 kHz, V: 60.00 Hz
|
||||||
|
geometry 1280 600 1280 600 32
|
||||||
|
timings 16260 184 28 18 1 128 3 endmode mode "1280x720-50"
|
||||||
|
# D: 60.466 MHz, H: 37.050 kHz, V: 50.00 Hz
|
||||||
|
geometry 1280 720 1280 720 32
|
||||||
|
timings 16538 176 48 17 1 128 3 endmode mode "1280x768-50"
|
||||||
|
# D: 65.178 MHz, H: 39.550 kHz, V: 50.00 Hz
|
||||||
|
geometry 1280 768 1280 768 32 timings 15342 184 28 19 1 128 3 endmode
|
||||||
|
#
|
||||||
|
# 1280x768, 60 Hz, Non-Interlaced (80.136 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 768
|
||||||
|
# Scan Frequency 47.700 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.697 us 0.063 ms
|
||||||
|
# 17 chars 3 lines
|
||||||
|
# Front Porch 0.799 us 0.021 ms
|
||||||
|
# 8 chars 1 lines
|
||||||
|
# Back Porch 2.496 us 0.483 ms
|
||||||
|
# 25 chars 23 lines
|
||||||
|
# Active Time 15.973 us 16.101 ms
|
||||||
|
# 160 chars 768 lines
|
||||||
|
# Blank Time 4.992 us 0.566 ms
|
||||||
|
# 50 chars 27 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1280x768-60"
|
||||||
|
# D: 80.13 MHz, H: 47.700 kHz, V: 60.00 Hz
|
||||||
|
geometry 1280 768 1280 768 32
|
||||||
|
timings 12480 200 48 23 1 126 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1280x800, 60 Hz, Non-Interlaced (83.375 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 800
|
||||||
|
# Scan Frequency 49.628 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.631 us 60.450 us
|
||||||
|
# 17 chars 3 lines
|
||||||
|
# Front Porch 0.768 us 20.15 us
|
||||||
|
# 8 chars 1 lines
|
||||||
|
# Back Porch 2.399 us 0.483 ms
|
||||||
|
# 25 chars 24 lines
|
||||||
|
# Active Time 15.352 us 16.120 ms
|
||||||
|
# 160 chars 800 lines
|
||||||
|
# Blank Time 4.798 us 0.564 ms
|
||||||
|
# 50 chars 28 lines
|
||||||
|
# Polarity negtive positive
|
||||||
|
#
|
||||||
|
mode "1280x800-60"
|
||||||
|
# D: 83.500 MHz, H: 49.702 kHz, V: 60.00 Hz
|
||||||
|
geometry 1280 800 1280 800 32 timings 11994 200 72 22 3 128 6 endmode
|
||||||
|
#
|
||||||
|
# 1280x960, 60 Hz, Non-Interlaced (108.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 960
|
||||||
|
# Scan Frequency 60.000 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.037 us 0.050 ms
|
||||||
|
# 14 chars 3 lines
|
||||||
|
# Front Porch 0.889 us 0.017 ms
|
||||||
|
# 12 chars 1 lines
|
||||||
|
# Back Porch 2.889 us 0.600 ms
|
||||||
|
# 39 chars 36 lines
|
||||||
|
# Active Time 11.852 us 16.000 ms
|
||||||
|
# 160 chars 960 lines
|
||||||
|
# Blank Time 4.815 us 0.667 ms
|
||||||
|
# 65 chars 40 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1280x960-60"
|
||||||
|
# D: 108.00 MHz, H: 60.000 kHz, V: 60.00 Hz
|
||||||
|
geometry 1280 960 1280 960 32
|
||||||
|
timings 9259 312 96 36 1 112 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1280x1024, 60 Hz, Non-Interlaced (108.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 1024
|
||||||
|
# Scan Frequency 63.981 kHz 60.02 Hz
|
||||||
|
# Sync Width 1.037 us 0.047 ms
|
||||||
|
# 14 chars 3 lines
|
||||||
|
# Front Porch 0.444 us 0.015 ms
|
||||||
|
# 6 chars 1 lines
|
||||||
|
# Back Porch 2.297 us 0.594 ms
|
||||||
|
# 31 chars 38 lines
|
||||||
|
# Active Time 11.852 us 16.005 ms
|
||||||
|
# 160 chars 1024 lines
|
||||||
|
# Blank Time 3.778 us 0.656 ms
|
||||||
|
# 51 chars 42 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1280x1024-60"
|
||||||
|
# D: 108.00 MHz, H: 63.981 kHz, V: 60.02 Hz
|
||||||
|
geometry 1280 1024 1280 1024 32
|
||||||
|
timings 9260 248 48 38 1 112 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1280x1024, 75 Hz, Non-Interlaced (135.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 1024
|
||||||
|
# Scan Frequency 79.976 kHz 75.02 Hz
|
||||||
|
# Sync Width 1.067 us 0.038 ms
|
||||||
|
# 18 chars 3 lines
|
||||||
|
# Front Porch 0.119 us 0.012 ms
|
||||||
|
# 2 chars 1 lines
|
||||||
|
# Back Porch 1.837 us 0.475 ms
|
||||||
|
# 31 chars 38 lines
|
||||||
|
# Active Time 9.481 us 12.804 ms
|
||||||
|
# 160 chars 1024 lines
|
||||||
|
# Blank Time 3.022 us 0.525 ms
|
||||||
|
# 51 chars 42 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1280x1024-75"
|
||||||
|
# D: 135.00 MHz, H: 79.976 kHz, V: 75.02 Hz
|
||||||
|
geometry 1280 1024 1280 1024 32
|
||||||
|
timings 7408 248 16 38 1 144 3 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1280x1024, 85 Hz, Non-Interlaced (157.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 1024
|
||||||
|
# Scan Frequency 91.146 kHz 85.02 Hz
|
||||||
|
# Sync Width 1.016 us 0.033 ms
|
||||||
|
# 20 chars 3 lines
|
||||||
|
# Front Porch 0.406 us 0.011 ms
|
||||||
|
# 8 chars 1 lines
|
||||||
|
# Back Porch 1.422 us 0.483 ms
|
||||||
|
# 28 chars 44 lines
|
||||||
|
# Active Time 8.127 us 11.235 ms
|
||||||
|
# 160 chars 1024 lines
|
||||||
|
# Blank Time 2.844 us 0.527 ms
|
||||||
|
# 56 chars 48 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1280x1024-85"
|
||||||
|
# D: 157.50 MHz, H: 91.146 kHz, V: 85.02 Hz
|
||||||
|
geometry 1280 1024 1280 1024 32
|
||||||
|
timings 6349 224 64 44 1 160 3
|
||||||
|
hsync high vsync high endmode mode "1440x900-60"
|
||||||
|
# D: 106.500 MHz, H: 55.935 kHz, V: 60.00 Hz
|
||||||
|
geometry 1440 900 1440 900 32
|
||||||
|
timings 9390 232 80 25 3 152 6
|
||||||
|
hsync high vsync high endmode mode "1440x900-75"
|
||||||
|
# D: 136.750 MHz, H: 70.635 kHz, V: 75.00 Hz
|
||||||
|
geometry 1440 900 1440 900 32
|
||||||
|
timings 7315 248 96 33 3 152 6 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1440x1050, 60 Hz, Non-Interlaced (125.10 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1440 1050
|
||||||
|
# Scan Frequency 65.220 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.204 us 0.046 ms
|
||||||
|
# 19 chars 3 lines
|
||||||
|
# Front Porch 0.760 us 0.015 ms
|
||||||
|
# 12 chars 1 lines
|
||||||
|
# Back Porch 1.964 us 0.495 ms
|
||||||
|
# 31 chars 33 lines
|
||||||
|
# Active Time 11.405 us 16.099 ms
|
||||||
|
# 180 chars 1050 lines
|
||||||
|
# Blank Time 3.928 us 0.567 ms
|
||||||
|
# 62 chars 37 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1440x1050-60"
|
||||||
|
# D: 125.10 MHz, H: 65.220 kHz, V: 60.00 Hz
|
||||||
|
geometry 1440 1050 1440 1050 32
|
||||||
|
timings 7993 248 96 33 1 152 3
|
||||||
|
hsync high vsync high endmode mode "1600x900-60"
|
||||||
|
# D: 118.250 MHz, H: 55.990 kHz, V: 60.00 Hz
|
||||||
|
geometry 1600 900 1600 900 32
|
||||||
|
timings 8415 256 88 26 3 168 5 endmode mode "1600x1024-60"
|
||||||
|
# D: 136.358 MHz, H: 63.600 kHz, V: 60.00 Hz
|
||||||
|
geometry 1600 1024 1600 1024 32 timings 7315 272 104 32 1 168 3 endmode
|
||||||
|
#
|
||||||
|
# 1600x1200, 60 Hz, Non-Interlaced (156.00 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1600 1200
|
||||||
|
# Scan Frequency 76.200 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.026 us 0.105 ms
|
||||||
|
# 20 chars 8 lines
|
||||||
|
# Front Porch 0.205 us 0.131 ms
|
||||||
|
# 4 chars 10 lines
|
||||||
|
# Back Porch 1.636 us 0.682 ms
|
||||||
|
# 32 chars 52 lines
|
||||||
|
# Active Time 10.256 us 15.748 ms
|
||||||
|
# 200 chars 1200 lines
|
||||||
|
# Blank Time 2.872 us 0.866 ms
|
||||||
|
# 56 chars 66 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "1600x1200-60"
|
||||||
|
# D: 156.00 MHz, H: 76.200 kHz, V: 60.00 Hz
|
||||||
|
geometry 1600 1200 1600 1200 32 timings 6172 256 32 52 10 160 8 endmode
|
||||||
|
#
|
||||||
|
# 1600x1200, 75 Hz, Non-Interlaced (202.50 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1600 1200
|
||||||
|
# Scan Frequency 93.750 kHz 75.00 Hz
|
||||||
|
# Sync Width 0.948 us 0.032 ms
|
||||||
|
# 24 chars 3 lines
|
||||||
|
# Front Porch 0.316 us 0.011 ms
|
||||||
|
# 8 chars 1 lines
|
||||||
|
# Back Porch 1.501 us 0.491 ms
|
||||||
|
# 38 chars 46 lines
|
||||||
|
# Active Time 7.901 us 12.800 ms
|
||||||
|
# 200 chars 1200 lines
|
||||||
|
# Blank Time 2.765 us 0.533 ms
|
||||||
|
# 70 chars 50 lines
|
||||||
|
# Polarity positive positive
|
||||||
|
#
|
||||||
|
mode "1600x1200-75"
|
||||||
|
# D: 202.50 MHz, H: 93.750 kHz, V: 75.00 Hz
|
||||||
|
geometry 1600 1200 1600 1200 32
|
||||||
|
timings 4938 304 64 46 1 192 3
|
||||||
|
hsync high vsync high endmode mode "1680x1050-60"
|
||||||
|
# D: 146.250 MHz, H: 65.290 kHz, V: 59.954 Hz
|
||||||
|
geometry 1680 1050 1680 1050 32
|
||||||
|
timings 6814 280 104 30 3 176 6
|
||||||
|
hsync high vsync high endmode mode "1680x1050-75"
|
||||||
|
# D: 187.000 MHz, H: 82.306 kHz, V: 74.892 Hz
|
||||||
|
geometry 1680 1050 1680 1050 32
|
||||||
|
timings 5348 296 120 40 3 176 6
|
||||||
|
hsync high vsync high endmode mode "1792x1344-60"
|
||||||
|
# D: 202.975 MHz, H: 83.460 kHz, V: 60.00 Hz
|
||||||
|
geometry 1792 1344 1792 1344 32
|
||||||
|
timings 4902 320 128 43 1 192 3
|
||||||
|
hsync high vsync high endmode mode "1856x1392-60"
|
||||||
|
# D: 218.571 MHz, H: 86.460 kHz, V: 60.00 Hz
|
||||||
|
geometry 1856 1392 1856 1392 32
|
||||||
|
timings 4577 336 136 45 1 200 3
|
||||||
|
hsync high vsync high endmode mode "1920x1200-60"
|
||||||
|
# D: 193.250 MHz, H: 74.556 kHz, V: 60.00 Hz
|
||||||
|
geometry 1920 1200 1920 1200 32
|
||||||
|
timings 5173 336 136 36 3 200 6
|
||||||
|
hsync high vsync high endmode mode "1920x1440-60"
|
||||||
|
# D: 234.000 MHz, H:90.000 kHz, V: 60.00 Hz
|
||||||
|
geometry 1920 1440 1920 1440 32
|
||||||
|
timings 4274 344 128 56 1 208 3
|
||||||
|
hsync high vsync high endmode mode "1920x1440-75"
|
||||||
|
# D: 297.000 MHz, H:112.500 kHz, V: 75.00 Hz
|
||||||
|
geometry 1920 1440 1920 1440 32
|
||||||
|
timings 3367 352 144 56 1 224 3
|
||||||
|
hsync high vsync high endmode mode "2048x1536-60"
|
||||||
|
# D: 267.250 MHz, H: 95.446 kHz, V: 60.00 Hz
|
||||||
|
geometry 2048 1536 2048 1536 32
|
||||||
|
timings 3742 376 152 49 3 224 4 hsync high vsync high endmode
|
||||||
|
#
|
||||||
|
# 1280x720, 60 Hz, Non-Interlaced (74.481 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1280 720
|
||||||
|
# Scan Frequency 44.760 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.826 us 67.024 ms
|
||||||
|
# 17 chars 3 lines
|
||||||
|
# Front Porch 0.752 us 22.341 ms
|
||||||
|
# 7 chars 1 lines
|
||||||
|
# Back Porch 2.578 us 491.510 ms
|
||||||
|
# 24 chars 22 lines
|
||||||
|
# Active Time 17.186 us 16.086 ms
|
||||||
|
# 160 chars 720 lines
|
||||||
|
# Blank Time 5.156 us 0.581 ms
|
||||||
|
# 48 chars 26 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "1280x720-60"
|
||||||
|
# D: 74.481 MHz, H: 44.760 kHz, V: 60.00 Hz
|
||||||
|
geometry 1280 720 1280 720 32 timings 13426 192 64 22 1 136 3 endmode
|
||||||
|
#
|
||||||
|
# 1920x1080, 60 Hz, Non-Interlaced (172.798 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1920 1080
|
||||||
|
# Scan Frequency 67.080 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.204 us 44.723 ms
|
||||||
|
# 26 chars 3 lines
|
||||||
|
# Front Porch 0.694 us 14.908 ms
|
||||||
|
# 15 chars 1 lines
|
||||||
|
# Back Porch 1.898 us 506.857 ms
|
||||||
|
# 41 chars 34 lines
|
||||||
|
# Active Time 11.111 us 16.100 ms
|
||||||
|
# 240 chars 1080 lines
|
||||||
|
# Blank Time 3.796 us 0.566 ms
|
||||||
|
# 82 chars 38 lines
|
||||||
|
# Polarity negative negative
|
||||||
|
#
|
||||||
|
mode "1920x1080-60"
|
||||||
|
# D: 74.481 MHz, H: 67.080 kHz, V: 60.00 Hz
|
||||||
|
geometry 1920 1080 1920 1080 32 timings 5787 328 120 34 1 208 3 endmode
|
||||||
|
#
|
||||||
|
# 1400x1050, 60 Hz, Non-Interlaced (122.61 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1400 1050
|
||||||
|
# Scan Frequency 65.218 kHz 59.99 Hz
|
||||||
|
# Sync Width 1.037 us 0.047 ms
|
||||||
|
# 19 chars 3 lines
|
||||||
|
# Front Porch 0.444 us 0.015 ms
|
||||||
|
# 11 chars 1 lines
|
||||||
|
# Back Porch 1.185 us 0.188 ms
|
||||||
|
# 30 chars 33 lines
|
||||||
|
# Active Time 12.963 us 16.411 ms
|
||||||
|
# 175 chars 1050 lines
|
||||||
|
# Blank Time 2.667 us 0.250 ms
|
||||||
|
# 60 chars 37 lines
|
||||||
|
# Polarity negative positive
|
||||||
|
#
|
||||||
|
mode "1400x1050-60"
|
||||||
|
# D: 122.750 MHz, H: 65.317 kHz, V: 59.99 Hz
|
||||||
|
geometry 1400 1050 1408 1050 32
|
||||||
|
timings 8214 232 88 32 3 144 4 endmode mode "1400x1050-75"
|
||||||
|
# D: 156.000 MHz, H: 82.278 kHz, V: 74.867 Hz
|
||||||
|
geometry 1400 1050 1408 1050 32 timings 6410 248 104 42 3 144 4 endmode
|
||||||
|
#
|
||||||
|
# 1366x768, 60 Hz, Non-Interlaced (85.86 MHz dotclock)
|
||||||
|
#
|
||||||
|
# Horizontal Vertical
|
||||||
|
# Resolution 1366 768
|
||||||
|
# Scan Frequency 47.700 kHz 60.00 Hz
|
||||||
|
# Sync Width 1.677 us 0.063 ms
|
||||||
|
# 18 chars 3 lines
|
||||||
|
# Front Porch 0.839 us 0.021 ms
|
||||||
|
# 9 chars 1 lines
|
||||||
|
# Back Porch 2.516 us 0.482 ms
|
||||||
|
# 27 chars 23 lines
|
||||||
|
# Active Time 15.933 us 16.101 ms
|
||||||
|
# 171 chars 768 lines
|
||||||
|
# Blank Time 5.031 us 0.566 ms
|
||||||
|
# 54 chars 27 lines
|
||||||
|
# Polarity negative positive
|
||||||
|
#
|
||||||
|
mode "1360x768-60"
|
||||||
|
# D: 84.750 MHz, H: 47.720 kHz, V: 60.00 Hz
|
||||||
|
geometry 1360 768 1360 768 32
|
||||||
|
timings 11799 208 72 22 3 136 5 endmode mode "1366x768-60"
|
||||||
|
# D: 85.86 MHz, H: 47.700 kHz, V: 60.00 Hz
|
||||||
|
geometry 1366 768 1366 768 32
|
||||||
|
timings 11647 216 72 23 1 144 3 endmode mode "1366x768-50"
|
||||||
|
# D: 69,924 MHz, H: 39.550 kHz, V: 50.00 Hz
|
||||||
|
geometry 1366 768 1366 768 32 timings 14301 200 56 19 1 144 3 endmode
|
|
@ -0,0 +1,214 @@
|
||||||
|
|
||||||
|
VIA Integration Graphic Chip Console Framebuffer Driver
|
||||||
|
|
||||||
|
[Platform]
|
||||||
|
-----------------------
|
||||||
|
The console framebuffer driver is for graphics chips of
|
||||||
|
VIA UniChrome Family(CLE266, PM800 / CN400 / CN300,
|
||||||
|
P4M800CE / P4M800Pro / CN700 / VN800,
|
||||||
|
CX700 / VX700, K8M890, P4M890,
|
||||||
|
CN896 / P4M900, VX800)
|
||||||
|
|
||||||
|
[Driver features]
|
||||||
|
------------------------
|
||||||
|
Device: CRT, LCD, DVI
|
||||||
|
|
||||||
|
Support viafb_mode:
|
||||||
|
CRT:
|
||||||
|
640x480(60, 75, 85, 100, 120 Hz), 720x480(60 Hz),
|
||||||
|
720x576(60 Hz), 800x600(60, 75, 85, 100, 120 Hz),
|
||||||
|
848x480(60 Hz), 856x480(60 Hz), 1024x512(60 Hz),
|
||||||
|
1024x768(60, 75, 85, 100 Hz), 1152x864(75 Hz),
|
||||||
|
1280x768(60 Hz), 1280x960(60 Hz), 1280x1024(60, 75, 85 Hz),
|
||||||
|
1440x1050(60 Hz), 1600x1200(60, 75 Hz), 1280x720(60 Hz),
|
||||||
|
1920x1080(60 Hz), 1400x1050(60 Hz), 800x480(60 Hz)
|
||||||
|
|
||||||
|
color depth: 8 bpp, 16 bpp, 32 bpp supports.
|
||||||
|
|
||||||
|
Support 2D hardware accelerator.
|
||||||
|
|
||||||
|
[Using the viafb module]
|
||||||
|
-- -- --------------------
|
||||||
|
Start viafb with default settings:
|
||||||
|
#modprobe viafb
|
||||||
|
|
||||||
|
Start viafb with with user options:
|
||||||
|
#modprobe viafb viafb_mode=800x600 viafb_bpp=16 viafb_refresh=60
|
||||||
|
viafb_active_dev=CRT+DVI viafb_dvi_port=DVP1
|
||||||
|
viafb_mode1=1024x768 viafb_bpp=16 viafb_refresh1=60
|
||||||
|
viafb_SAMM_ON=1
|
||||||
|
|
||||||
|
viafb_mode:
|
||||||
|
640x480 (default)
|
||||||
|
720x480
|
||||||
|
800x600
|
||||||
|
1024x768
|
||||||
|
......
|
||||||
|
|
||||||
|
viafb_bpp:
|
||||||
|
8, 16, 32 (default:32)
|
||||||
|
|
||||||
|
viafb_refresh:
|
||||||
|
60, 75, 85, 100, 120 (default:60)
|
||||||
|
|
||||||
|
viafb_lcd_dsp_method:
|
||||||
|
0 : expansion (default)
|
||||||
|
1 : centering
|
||||||
|
|
||||||
|
viafb_lcd_mode:
|
||||||
|
0 : LCD panel with LSB data format input (default)
|
||||||
|
1 : LCD panel with MSB data format input
|
||||||
|
|
||||||
|
viafb_lcd_panel_id:
|
||||||
|
0 : Resolution: 640x480, Channel: single, Dithering: Enable
|
||||||
|
1 : Resolution: 800x600, Channel: single, Dithering: Enable
|
||||||
|
2 : Resolution: 1024x768, Channel: single, Dithering: Enable (default)
|
||||||
|
3 : Resolution: 1280x768, Channel: single, Dithering: Enable
|
||||||
|
4 : Resolution: 1280x1024, Channel: dual, Dithering: Enable
|
||||||
|
5 : Resolution: 1400x1050, Channel: dual, Dithering: Enable
|
||||||
|
6 : Resolution: 1600x1200, Channel: dual, Dithering: Enable
|
||||||
|
|
||||||
|
8 : Resolution: 800x480, Channel: single, Dithering: Enable
|
||||||
|
9 : Resolution: 1024x768, Channel: dual, Dithering: Enable
|
||||||
|
10: Resolution: 1024x768, Channel: single, Dithering: Disable
|
||||||
|
11: Resolution: 1024x768, Channel: dual, Dithering: Disable
|
||||||
|
12: Resolution: 1280x768, Channel: single, Dithering: Disable
|
||||||
|
13: Resolution: 1280x1024, Channel: dual, Dithering: Disable
|
||||||
|
14: Resolution: 1400x1050, Channel: dual, Dithering: Disable
|
||||||
|
15: Resolution: 1600x1200, Channel: dual, Dithering: Disable
|
||||||
|
16: Resolution: 1366x768, Channel: single, Dithering: Disable
|
||||||
|
17: Resolution: 1024x600, Channel: single, Dithering: Enable
|
||||||
|
18: Resolution: 1280x768, Channel: dual, Dithering: Enable
|
||||||
|
19: Resolution: 1280x800, Channel: single, Dithering: Enable
|
||||||
|
|
||||||
|
viafb_accel:
|
||||||
|
0 : No 2D Hardware Acceleration
|
||||||
|
1 : 2D Hardware Acceleration (default)
|
||||||
|
|
||||||
|
viafb_SAMM_ON:
|
||||||
|
0 : viafb_SAMM_ON disable (default)
|
||||||
|
1 : viafb_SAMM_ON enable
|
||||||
|
|
||||||
|
viafb_mode1: (secondary display device)
|
||||||
|
640x480 (default)
|
||||||
|
720x480
|
||||||
|
800x600
|
||||||
|
1024x768
|
||||||
|
... ...
|
||||||
|
|
||||||
|
viafb_bpp1: (secondary display device)
|
||||||
|
8, 16, 32 (default:32)
|
||||||
|
|
||||||
|
viafb_refresh1: (secondary display device)
|
||||||
|
60, 75, 85, 100, 120 (default:60)
|
||||||
|
|
||||||
|
viafb_active_dev:
|
||||||
|
This option is used to specify active devices.(CRT, DVI, CRT+LCD...)
|
||||||
|
DVI stands for DVI or HDMI, E.g., If you want to enable HDMI,
|
||||||
|
set viafb_active_dev=DVI. In SAMM case, the previous of
|
||||||
|
viafb_active_dev is primary device, and the following is
|
||||||
|
secondary device.
|
||||||
|
|
||||||
|
For example:
|
||||||
|
To enable one device, such as DVI only, we can use:
|
||||||
|
modprobe viafb viafb_active_dev=DVI
|
||||||
|
To enable two devices, such as CRT+DVI:
|
||||||
|
modprobe viafb viafb_active_dev=CRT+DVI;
|
||||||
|
|
||||||
|
For DuoView case, we can use:
|
||||||
|
modprobe viafb viafb_active_dev=CRT+DVI
|
||||||
|
OR
|
||||||
|
modprobe viafb viafb_active_dev=DVI+CRT...
|
||||||
|
|
||||||
|
For SAMM case:
|
||||||
|
If CRT is primary and DVI is secondary, we should use:
|
||||||
|
modprobe viafb viafb_active_dev=CRT+DVI viafb_SAMM_ON=1...
|
||||||
|
If DVI is primary and CRT is secondary, we should use:
|
||||||
|
modprobe viafb viafb_active_dev=DVI+CRT viafb_SAMM_ON=1...
|
||||||
|
|
||||||
|
viafb_display_hardware_layout:
|
||||||
|
This option is used to specify display hardware layout for CX700 chip.
|
||||||
|
1 : LCD only
|
||||||
|
2 : DVI only
|
||||||
|
3 : LCD+DVI (default)
|
||||||
|
4 : LCD1+LCD2 (internal + internal)
|
||||||
|
16: LCD1+ExternalLCD2 (internal + external)
|
||||||
|
|
||||||
|
viafb_second_size:
|
||||||
|
This option is used to set second device memory size(MB) in SAMM case.
|
||||||
|
The minimal size is 16.
|
||||||
|
|
||||||
|
viafb_platform_epia_dvi:
|
||||||
|
This option is used to enable DVI on EPIA - M
|
||||||
|
0 : No DVI on EPIA - M (default)
|
||||||
|
1 : DVI on EPIA - M
|
||||||
|
|
||||||
|
viafb_bus_width:
|
||||||
|
When using 24 - Bit Bus Width Digital Interface,
|
||||||
|
this option should be set.
|
||||||
|
12: 12-Bit LVDS or 12-Bit TMDS (default)
|
||||||
|
24: 24-Bit LVDS or 24-Bit TMDS
|
||||||
|
|
||||||
|
viafb_device_lcd_dualedge:
|
||||||
|
When using Dual Edge Panel, this option should be set.
|
||||||
|
0 : No Dual Edge Panel (default)
|
||||||
|
1 : Dual Edge Panel
|
||||||
|
|
||||||
|
viafb_video_dev:
|
||||||
|
This option is used to specify video output devices(CRT, DVI, LCD) for
|
||||||
|
duoview case.
|
||||||
|
For example:
|
||||||
|
To output video on DVI, we should use:
|
||||||
|
modprobe viafb viafb_video_dev=DVI...
|
||||||
|
|
||||||
|
viafb_lcd_port:
|
||||||
|
This option is used to specify LCD output port,
|
||||||
|
available values are "DVP0" "DVP1" "DFP_HIGHLOW" "DFP_HIGH" "DFP_LOW".
|
||||||
|
for external LCD + external DVI on CX700(External LCD is on DVP0),
|
||||||
|
we should use:
|
||||||
|
modprobe viafb viafb_lcd_port=DVP0...
|
||||||
|
|
||||||
|
Notes:
|
||||||
|
1. CRT may not display properly for DuoView CRT & DVI display at
|
||||||
|
the "640x480" PAL mode with DVI overscan enabled.
|
||||||
|
2. SAMM stands for single adapter multi monitors. It is different from
|
||||||
|
multi-head since SAMM support multi monitor at driver layers, thus fbcon
|
||||||
|
layer doesn't even know about it; SAMM's second screen doesn't have a
|
||||||
|
device node file, thus a user mode application can't access it directly.
|
||||||
|
When SAMM is enabled, viafb_mode and viafb_mode1, viafb_bpp and
|
||||||
|
viafb_bpp1, viafb_refresh and viafb_refresh1 can be different.
|
||||||
|
3. When console is depending on viafbinfo1, dynamically change resolution
|
||||||
|
and bpp, need to call VIAFB specified ioctl interface VIAFB_SET_DEVICE
|
||||||
|
instead of calling common ioctl function FBIOPUT_VSCREENINFO since
|
||||||
|
viafb doesn't support multi-head well, or it will cause screen crush.
|
||||||
|
4. VX800 2D accelerator hasn't been supported in this driver yet. When
|
||||||
|
using driver on VX800, the driver will disable the acceleration
|
||||||
|
function as default.
|
||||||
|
|
||||||
|
|
||||||
|
[Configure viafb with "fbset" tool]
|
||||||
|
-----------------------------------
|
||||||
|
"fbset" is an inbox utility of Linux.
|
||||||
|
1. Inquire current viafb information, type,
|
||||||
|
# fbset -i
|
||||||
|
|
||||||
|
2. Set various resolutions and viafb_refresh rates,
|
||||||
|
# fbset <resolution-vertical_sync>
|
||||||
|
|
||||||
|
example,
|
||||||
|
# fbset "1024x768-75"
|
||||||
|
or
|
||||||
|
# fbset -g 1024 768 1024 768 32
|
||||||
|
Check the file "/etc/fb.modes" to find display modes available.
|
||||||
|
|
||||||
|
3. Set the color depth,
|
||||||
|
# fbset -depth <value>
|
||||||
|
|
||||||
|
example,
|
||||||
|
# fbset -depth 16
|
||||||
|
|
||||||
|
[Bootup with viafb]:
|
||||||
|
--------------------
|
||||||
|
Add the following line to your grub.conf:
|
||||||
|
append = "video=viafb:viafb_mode=1024x768,viafb_bpp=32,viafb_refresh=85"
|
||||||
|
|
|
@ -6,6 +6,24 @@ be removed from this file.
|
||||||
|
|
||||||
---------------------------
|
---------------------------
|
||||||
|
|
||||||
|
What: old static regulatory information and ieee80211_regdom module parameter
|
||||||
|
When: 2.6.29
|
||||||
|
Why: The old regulatory infrastructure has been replaced with a new one
|
||||||
|
which does not require statically defined regulatory domains. We do
|
||||||
|
not want to keep static regulatory domains in the kernel due to the
|
||||||
|
the dynamic nature of regulatory law and localization. We kept around
|
||||||
|
the old static definitions for the regulatory domains of:
|
||||||
|
* US
|
||||||
|
* JP
|
||||||
|
* EU
|
||||||
|
and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
|
||||||
|
set. We also kept around the ieee80211_regdom module parameter in case
|
||||||
|
some applications were relying on it. Changing regulatory domains
|
||||||
|
can now be done instead by using nl80211, as is done with iw.
|
||||||
|
Who: Luis R. Rodriguez <lrodriguez@atheros.com>
|
||||||
|
|
||||||
|
---------------------------
|
||||||
|
|
||||||
What: dev->power.power_state
|
What: dev->power.power_state
|
||||||
When: July 2007
|
When: July 2007
|
||||||
Why: Broken design for runtime control over driver power states, confusing
|
Why: Broken design for runtime control over driver power states, confusing
|
||||||
|
@ -232,6 +250,9 @@ What (Why):
|
||||||
- xt_mark match revision 0
|
- xt_mark match revision 0
|
||||||
(superseded by xt_mark match revision 1)
|
(superseded by xt_mark match revision 1)
|
||||||
|
|
||||||
|
- xt_recent: the old ipt_recent proc dir
|
||||||
|
(superseded by /proc/net/xt_recent)
|
||||||
|
|
||||||
When: January 2009 or Linux 2.7.0, whichever comes first
|
When: January 2009 or Linux 2.7.0, whichever comes first
|
||||||
Why: Superseded by newer revisions or modules
|
Why: Superseded by newer revisions or modules
|
||||||
Who: Jan Engelhardt <jengelh@computergmbh.de>
|
Who: Jan Engelhardt <jengelh@computergmbh.de>
|
||||||
|
@ -266,11 +287,19 @@ Who: Glauber Costa <gcosta@redhat.com>
|
||||||
|
|
||||||
---------------------------
|
---------------------------
|
||||||
|
|
||||||
What: old style serial driver for ColdFire (CONFIG_SERIAL_COLDFIRE)
|
What: remove HID compat support
|
||||||
When: 2.6.28
|
When: 2.6.29
|
||||||
Why: This driver still uses the old interface and has been replaced
|
Why: needed only as a temporary solution until distros fix themselves up
|
||||||
by CONFIG_SERIAL_MCF.
|
Who: Jiri Slaby <jirislaby@gmail.com>
|
||||||
Who: Sebastian Siewior <sebastian@breakpoint.cc>
|
|
||||||
|
---------------------------
|
||||||
|
|
||||||
|
What: print_fn_descriptor_symbol()
|
||||||
|
When: October 2009
|
||||||
|
Why: The %pF vsprintf format provides the same functionality in a
|
||||||
|
simpler way. print_fn_descriptor_symbol() is deprecated but
|
||||||
|
still present to give out-of-tree modules time to change.
|
||||||
|
Who: Bjorn Helgaas <bjorn.helgaas@hp.com>
|
||||||
|
|
||||||
---------------------------
|
---------------------------
|
||||||
|
|
||||||
|
|
|
@ -0,0 +1,393 @@
|
||||||
|
|
||||||
|
Miscellaneous Device control operations for the autofs4 kernel module
|
||||||
|
====================================================================
|
||||||
|
|
||||||
|
The problem
|
||||||
|
===========
|
||||||
|
|
||||||
|
There is a problem with active restarts in autofs (that is to say
|
||||||
|
restarting autofs when there are busy mounts).
|
||||||
|
|
||||||
|
During normal operation autofs uses a file descriptor opened on the
|
||||||
|
directory that is being managed in order to be able to issue control
|
||||||
|
operations. Using a file descriptor gives ioctl operations access to
|
||||||
|
autofs specific information stored in the super block. The operations
|
||||||
|
are things such as setting an autofs mount catatonic, setting the
|
||||||
|
expire timeout and requesting expire checks. As is explained below,
|
||||||
|
certain types of autofs triggered mounts can end up covering an autofs
|
||||||
|
mount itself which prevents us being able to use open(2) to obtain a
|
||||||
|
file descriptor for these operations if we don't already have one open.
|
||||||
|
|
||||||
|
Currently autofs uses "umount -l" (lazy umount) to clear active mounts
|
||||||
|
at restart. While using lazy umount works for most cases, anything that
|
||||||
|
needs to walk back up the mount tree to construct a path, such as
|
||||||
|
getcwd(2) and the proc file system /proc/<pid>/cwd, no longer works
|
||||||
|
because the point from which the path is constructed has been detached
|
||||||
|
from the mount tree.
|
||||||
|
|
||||||
|
The actual problem with autofs is that it can't reconnect to existing
|
||||||
|
mounts. Immediately one thinks of just adding the ability to remount
|
||||||
|
autofs file systems would solve it, but alas, that can't work. This is
|
||||||
|
because autofs direct mounts and the implementation of "on demand mount
|
||||||
|
and expire" of nested mount trees have the file system mounted directly
|
||||||
|
on top of the mount trigger directory dentry.
|
||||||
|
|
||||||
|
For example, there are two types of automount maps, direct (in the kernel
|
||||||
|
module source you will see a third type called an offset, which is just
|
||||||
|
a direct mount in disguise) and indirect.
|
||||||
|
|
||||||
|
Here is a master map with direct and indirect map entries:
|
||||||
|
|
||||||
|
/- /etc/auto.direct
|
||||||
|
/test /etc/auto.indirect
|
||||||
|
|
||||||
|
and the corresponding map files:
|
||||||
|
|
||||||
|
/etc/auto.direct:
|
||||||
|
|
||||||
|
/automount/dparse/g6 budgie:/autofs/export1
|
||||||
|
/automount/dparse/g1 shark:/autofs/export1
|
||||||
|
and so on.
|
||||||
|
|
||||||
|
/etc/auto.indirect:
|
||||||
|
|
||||||
|
g1 shark:/autofs/export1
|
||||||
|
g6 budgie:/autofs/export1
|
||||||
|
and so on.
|
||||||
|
|
||||||
|
For the above indirect map an autofs file system is mounted on /test and
|
||||||
|
mounts are triggered for each sub-directory key by the inode lookup
|
||||||
|
operation. So we see a mount of shark:/autofs/export1 on /test/g1, for
|
||||||
|
example.
|
||||||
|
|
||||||
|
The way that direct mounts are handled is by making an autofs mount on
|
||||||
|
each full path, such as /automount/dparse/g1, and using it as a mount
|
||||||
|
trigger. So when we walk on the path we mount shark:/autofs/export1 "on
|
||||||
|
top of this mount point". Since these are always directories we can
|
||||||
|
use the follow_link inode operation to trigger the mount.
|
||||||
|
|
||||||
|
But, each entry in direct and indirect maps can have offsets (making
|
||||||
|
them multi-mount map entries).
|
||||||
|
|
||||||
|
For example, an indirect mount map entry could also be:
|
||||||
|
|
||||||
|
g1 \
|
||||||
|
/ shark:/autofs/export5/testing/test \
|
||||||
|
/s1 shark:/autofs/export/testing/test/s1 \
|
||||||
|
/s2 shark:/autofs/export5/testing/test/s2 \
|
||||||
|
/s1/ss1 shark:/autofs/export1 \
|
||||||
|
/s2/ss2 shark:/autofs/export2
|
||||||
|
|
||||||
|
and a similarly a direct mount map entry could also be:
|
||||||
|
|
||||||
|
/automount/dparse/g1 \
|
||||||
|
/ shark:/autofs/export5/testing/test \
|
||||||
|
/s1 shark:/autofs/export/testing/test/s1 \
|
||||||
|
/s2 shark:/autofs/export5/testing/test/s2 \
|
||||||
|
/s1/ss1 shark:/autofs/export2 \
|
||||||
|
/s2/ss2 shark:/autofs/export2
|
||||||
|
|
||||||
|
One of the issues with version 4 of autofs was that, when mounting an
|
||||||
|
entry with a large number of offsets, possibly with nesting, we needed
|
||||||
|
to mount and umount all of the offsets as a single unit. Not really a
|
||||||
|
problem, except for people with a large number of offsets in map entries.
|
||||||
|
This mechanism is used for the well known "hosts" map and we have seen
|
||||||
|
cases (in 2.4) where the available number of mounts are exhausted or
|
||||||
|
where the number of privileged ports available is exhausted.
|
||||||
|
|
||||||
|
In version 5 we mount only as we go down the tree of offsets and
|
||||||
|
similarly for expiring them which resolves the above problem. There is
|
||||||
|
somewhat more detail to the implementation but it isn't needed for the
|
||||||
|
sake of the problem explanation. The one important detail is that these
|
||||||
|
offsets are implemented using the same mechanism as the direct mounts
|
||||||
|
above and so the mount points can be covered by a mount.
|
||||||
|
|
||||||
|
The current autofs implementation uses an ioctl file descriptor opened
|
||||||
|
on the mount point for control operations. The references held by the
|
||||||
|
descriptor are accounted for in checks made to determine if a mount is
|
||||||
|
in use and is also used to access autofs file system information held
|
||||||
|
in the mount super block. So the use of a file handle needs to be
|
||||||
|
retained.
|
||||||
|
|
||||||
|
|
||||||
|
The Solution
|
||||||
|
============
|
||||||
|
|
||||||
|
To be able to restart autofs leaving existing direct, indirect and
|
||||||
|
offset mounts in place we need to be able to obtain a file handle
|
||||||
|
for these potentially covered autofs mount points. Rather than just
|
||||||
|
implement an isolated operation it was decided to re-implement the
|
||||||
|
existing ioctl interface and add new operations to provide this
|
||||||
|
functionality.
|
||||||
|
|
||||||
|
In addition, to be able to reconstruct a mount tree that has busy mounts,
|
||||||
|
the uid and gid of the last user that triggered the mount needs to be
|
||||||
|
available because these can be used as macro substitution variables in
|
||||||
|
autofs maps. They are recorded at mount request time and an operation
|
||||||
|
has been added to retrieve them.
|
||||||
|
|
||||||
|
Since we're re-implementing the control interface, a couple of other
|
||||||
|
problems with the existing interface have been addressed. First, when
|
||||||
|
a mount or expire operation completes a status is returned to the
|
||||||
|
kernel by either a "send ready" or a "send fail" operation. The
|
||||||
|
"send fail" operation of the ioctl interface could only ever send
|
||||||
|
ENOENT so the re-implementation allows user space to send an actual
|
||||||
|
status. Another expensive operation in user space, for those using
|
||||||
|
very large maps, is discovering if a mount is present. Usually this
|
||||||
|
involves scanning /proc/mounts and since it needs to be done quite
|
||||||
|
often it can introduce significant overhead when there are many entries
|
||||||
|
in the mount table. An operation to lookup the mount status of a mount
|
||||||
|
point dentry (covered or not) has also been added.
|
||||||
|
|
||||||
|
Current kernel development policy recommends avoiding the use of the
|
||||||
|
ioctl mechanism in favor of systems such as Netlink. An implementation
|
||||||
|
using this system was attempted to evaluate its suitability and it was
|
||||||
|
found to be inadequate, in this case. The Generic Netlink system was
|
||||||
|
used for this as raw Netlink would lead to a significant increase in
|
||||||
|
complexity. There's no question that the Generic Netlink system is an
|
||||||
|
elegant solution for common case ioctl functions but it's not a complete
|
||||||
|
replacement probably because it's primary purpose in life is to be a
|
||||||
|
message bus implementation rather than specifically an ioctl replacement.
|
||||||
|
While it would be possible to work around this there is one concern
|
||||||
|
that lead to the decision to not use it. This is that the autofs
|
||||||
|
expire in the daemon has become far to complex because umount
|
||||||
|
candidates are enumerated, almost for no other reason than to "count"
|
||||||
|
the number of times to call the expire ioctl. This involves scanning
|
||||||
|
the mount table which has proved to be a big overhead for users with
|
||||||
|
large maps. The best way to improve this is try and get back to the
|
||||||
|
way the expire was done long ago. That is, when an expire request is
|
||||||
|
issued for a mount (file handle) we should continually call back to
|
||||||
|
the daemon until we can't umount any more mounts, then return the
|
||||||
|
appropriate status to the daemon. At the moment we just expire one
|
||||||
|
mount at a time. A Generic Netlink implementation would exclude this
|
||||||
|
possibility for future development due to the requirements of the
|
||||||
|
message bus architecture.
|
||||||
|
|
||||||
|
|
||||||
|
autofs4 Miscellaneous Device mount control interface
|
||||||
|
====================================================
|
||||||
|
|
||||||
|
The control interface is opening a device node, typically /dev/autofs.
|
||||||
|
|
||||||
|
All the ioctls use a common structure to pass the needed parameter
|
||||||
|
information and return operation results:
|
||||||
|
|
||||||
|
struct autofs_dev_ioctl {
|
||||||
|
__u32 ver_major;
|
||||||
|
__u32 ver_minor;
|
||||||
|
__u32 size; /* total size of data passed in
|
||||||
|
* including this struct */
|
||||||
|
__s32 ioctlfd; /* automount command fd */
|
||||||
|
|
||||||
|
__u32 arg1; /* Command parameters */
|
||||||
|
__u32 arg2;
|
||||||
|
|
||||||
|
char path[0];
|
||||||
|
};
|
||||||
|
|
||||||
|
The ioctlfd field is a mount point file descriptor of an autofs mount
|
||||||
|
point. It is returned by the open call and is used by all calls except
|
||||||
|
the check for whether a given path is a mount point, where it may
|
||||||
|
optionally be used to check a specific mount corresponding to a given
|
||||||
|
mount point file descriptor, and when requesting the uid and gid of the
|
||||||
|
last successful mount on a directory within the autofs file system.
|
||||||
|
|
||||||
|
The fields arg1 and arg2 are used to communicate parameters and results of
|
||||||
|
calls made as described below.
|
||||||
|
|
||||||
|
The path field is used to pass a path where it is needed and the size field
|
||||||
|
is used account for the increased structure length when translating the
|
||||||
|
structure sent from user space.
|
||||||
|
|
||||||
|
This structure can be initialized before setting specific fields by using
|
||||||
|
the void function call init_autofs_dev_ioctl(struct autofs_dev_ioctl *).
|
||||||
|
|
||||||
|
All of the ioctls perform a copy of this structure from user space to
|
||||||
|
kernel space and return -EINVAL if the size parameter is smaller than
|
||||||
|
the structure size itself, -ENOMEM if the kernel memory allocation fails
|
||||||
|
or -EFAULT if the copy itself fails. Other checks include a version check
|
||||||
|
of the compiled in user space version against the module version and a
|
||||||
|
mismatch results in a -EINVAL return. If the size field is greater than
|
||||||
|
the structure size then a path is assumed to be present and is checked to
|
||||||
|
ensure it begins with a "/" and is NULL terminated, otherwise -EINVAL is
|
||||||
|
returned. Following these checks, for all ioctl commands except
|
||||||
|
AUTOFS_DEV_IOCTL_VERSION_CMD, AUTOFS_DEV_IOCTL_OPENMOUNT_CMD and
|
||||||
|
AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD the ioctlfd is validated and if it is
|
||||||
|
not a valid descriptor or doesn't correspond to an autofs mount point
|
||||||
|
an error of -EBADF, -ENOTTY or -EINVAL (not an autofs descriptor) is
|
||||||
|
returned.
|
||||||
|
|
||||||
|
|
||||||
|
The ioctls
|
||||||
|
==========
|
||||||
|
|
||||||
|
An example of an implementation which uses this interface can be seen
|
||||||
|
in autofs version 5.0.4 and later in file lib/dev-ioctl-lib.c of the
|
||||||
|
distribution tar available for download from kernel.org in directory
|
||||||
|
/pub/linux/daemons/autofs/v5.
|
||||||
|
|
||||||
|
The device node ioctl operations implemented by this interface are:
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_VERSION
|
||||||
|
------------------------
|
||||||
|
|
||||||
|
Get the major and minor version of the autofs4 device ioctl kernel module
|
||||||
|
implementation. It requires an initialized struct autofs_dev_ioctl as an
|
||||||
|
input parameter and sets the version information in the passed in structure.
|
||||||
|
It returns 0 on success or the error -EINVAL if a version mismatch is
|
||||||
|
detected.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD
|
||||||
|
------------------------------------------------------------------
|
||||||
|
|
||||||
|
Get the major and minor version of the autofs4 protocol version understood
|
||||||
|
by loaded module. This call requires an initialized struct autofs_dev_ioctl
|
||||||
|
with the ioctlfd field set to a valid autofs mount point descriptor
|
||||||
|
and sets the requested version number in structure field arg1. These
|
||||||
|
commands return 0 on success or one of the negative error codes if
|
||||||
|
validation fails.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_OPENMOUNT and AUTOFS_DEV_IOCTL_CLOSEMOUNT
|
||||||
|
----------------------------------------------------------
|
||||||
|
|
||||||
|
Obtain and release a file descriptor for an autofs managed mount point
|
||||||
|
path. The open call requires an initialized struct autofs_dev_ioctl with
|
||||||
|
the the path field set and the size field adjusted appropriately as well
|
||||||
|
as the arg1 field set to the device number of the autofs mount. The
|
||||||
|
device number can be obtained from the mount options shown in
|
||||||
|
/proc/mounts. The close call requires an initialized struct
|
||||||
|
autofs_dev_ioct with the ioctlfd field set to the descriptor obtained
|
||||||
|
from the open call. The release of the file descriptor can also be done
|
||||||
|
with close(2) so any open descriptors will also be closed at process exit.
|
||||||
|
The close call is included in the implemented operations largely for
|
||||||
|
completeness and to provide for a consistent user space implementation.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_READY_CMD and AUTOFS_DEV_IOCTL_FAIL_CMD
|
||||||
|
--------------------------------------------------------
|
||||||
|
|
||||||
|
Return mount and expire result status from user space to the kernel.
|
||||||
|
Both of these calls require an initialized struct autofs_dev_ioctl
|
||||||
|
with the ioctlfd field set to the descriptor obtained from the open
|
||||||
|
call and the arg1 field set to the wait queue token number, received
|
||||||
|
by user space in the foregoing mount or expire request. The arg2 field
|
||||||
|
is set to the status to be returned. For the ready call this is always
|
||||||
|
0 and for the fail call it is set to the errno of the operation.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_SETPIPEFD_CMD
|
||||||
|
------------------------------
|
||||||
|
|
||||||
|
Set the pipe file descriptor used for kernel communication to the daemon.
|
||||||
|
Normally this is set at mount time using an option but when reconnecting
|
||||||
|
to a existing mount we need to use this to tell the autofs mount about
|
||||||
|
the new kernel pipe descriptor. In order to protect mounts against
|
||||||
|
incorrectly setting the pipe descriptor we also require that the autofs
|
||||||
|
mount be catatonic (see next call).
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the
|
||||||
|
ioctlfd field set to the descriptor obtained from the open call and
|
||||||
|
the arg1 field set to descriptor of the pipe. On success the call
|
||||||
|
also sets the process group id used to identify the controlling process
|
||||||
|
(eg. the owning automount(8) daemon) to the process group of the caller.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_CATATONIC_CMD
|
||||||
|
------------------------------
|
||||||
|
|
||||||
|
Make the autofs mount point catatonic. The autofs mount will no longer
|
||||||
|
issue mount requests, the kernel communication pipe descriptor is released
|
||||||
|
and any remaining waits in the queue released.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the
|
||||||
|
ioctlfd field set to the descriptor obtained from the open call.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_TIMEOUT_CMD
|
||||||
|
----------------------------
|
||||||
|
|
||||||
|
Set the expire timeout for mounts withing an autofs mount point.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the
|
||||||
|
ioctlfd field set to the descriptor obtained from the open call.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_REQUESTER_CMD
|
||||||
|
------------------------------
|
||||||
|
|
||||||
|
Return the uid and gid of the last process to successfully trigger a the
|
||||||
|
mount on the given path dentry.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the path
|
||||||
|
field set to the mount point in question and the size field adjusted
|
||||||
|
appropriately as well as the arg1 field set to the device number of the
|
||||||
|
containing autofs mount. Upon return the struct field arg1 contains the
|
||||||
|
uid and arg2 the gid.
|
||||||
|
|
||||||
|
When reconstructing an autofs mount tree with active mounts we need to
|
||||||
|
re-connect to mounts that may have used the original process uid and
|
||||||
|
gid (or string variations of them) for mount lookups within the map entry.
|
||||||
|
This call provides the ability to obtain this uid and gid so they may be
|
||||||
|
used by user space for the mount map lookups.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_EXPIRE_CMD
|
||||||
|
---------------------------
|
||||||
|
|
||||||
|
Issue an expire request to the kernel for an autofs mount. Typically
|
||||||
|
this ioctl is called until no further expire candidates are found.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the
|
||||||
|
ioctlfd field set to the descriptor obtained from the open call. In
|
||||||
|
addition an immediate expire, independent of the mount timeout, can be
|
||||||
|
requested by setting the arg1 field to 1. If no expire candidates can
|
||||||
|
be found the ioctl returns -1 with errno set to EAGAIN.
|
||||||
|
|
||||||
|
This call causes the kernel module to check the mount corresponding
|
||||||
|
to the given ioctlfd for mounts that can be expired, issues an expire
|
||||||
|
request back to the daemon and waits for completion.
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD
|
||||||
|
------------------------------
|
||||||
|
|
||||||
|
Checks if an autofs mount point is in use.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl with the
|
||||||
|
ioctlfd field set to the descriptor obtained from the open call and
|
||||||
|
it returns the result in the arg1 field, 1 for busy and 0 otherwise.
|
||||||
|
|
||||||
|
|
||||||
|
AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
|
||||||
|
---------------------------------
|
||||||
|
|
||||||
|
Check if the given path is a mountpoint.
|
||||||
|
|
||||||
|
The call requires an initialized struct autofs_dev_ioctl. There are two
|
||||||
|
possible variations. Both use the path field set to the path of the mount
|
||||||
|
point to check and the size field adjusted appropriately. One uses the
|
||||||
|
ioctlfd field to identify a specific mount point to check while the other
|
||||||
|
variation uses the path and optionaly arg1 set to an autofs mount type.
|
||||||
|
The call returns 1 if this is a mount point and sets arg1 to the device
|
||||||
|
number of the mount and field arg2 to the relevant super block magic
|
||||||
|
number (described below) or 0 if it isn't a mountpoint. In both cases
|
||||||
|
the the device number (as returned by new_encode_dev()) is returned
|
||||||
|
in field arg1.
|
||||||
|
|
||||||
|
If supplied with a file descriptor we're looking for a specific mount,
|
||||||
|
not necessarily at the top of the mounted stack. In this case the path
|
||||||
|
the descriptor corresponds to is considered a mountpoint if it is itself
|
||||||
|
a mountpoint or contains a mount, such as a multi-mount without a root
|
||||||
|
mount. In this case we return 1 if the descriptor corresponds to a mount
|
||||||
|
point and and also returns the super magic of the covering mount if there
|
||||||
|
is one or 0 if it isn't a mountpoint.
|
||||||
|
|
||||||
|
If a path is supplied (and the ioctlfd field is set to -1) then the path
|
||||||
|
is looked up and is checked to see if it is the root of a mount. If a
|
||||||
|
type is also given we are looking for a particular autofs mount and if
|
||||||
|
a match isn't found a fail is returned. If the the located path is the
|
||||||
|
root of a mount 1 is returned along with the super magic of the mount
|
||||||
|
or 0 otherwise.
|
||||||
|
|
|
@ -96,6 +96,11 @@ errors=remount-ro(*) Remount the filesystem read-only on an error.
|
||||||
errors=continue Keep going on a filesystem error.
|
errors=continue Keep going on a filesystem error.
|
||||||
errors=panic Panic and halt the machine if an error occurs.
|
errors=panic Panic and halt the machine if an error occurs.
|
||||||
|
|
||||||
|
data_err=ignore(*) Just print an error message if an error occurs
|
||||||
|
in a file data buffer in ordered mode.
|
||||||
|
data_err=abort Abort the journal if an error occurs in a file
|
||||||
|
data buffer in ordered mode.
|
||||||
|
|
||||||
grpid Give objects the same group ID as their creator.
|
grpid Give objects the same group ID as their creator.
|
||||||
bsdgroups
|
bsdgroups
|
||||||
|
|
||||||
|
@ -193,6 +198,5 @@ kernel source: <file:fs/ext3/>
|
||||||
programs: http://e2fsprogs.sourceforge.net/
|
programs: http://e2fsprogs.sourceforge.net/
|
||||||
http://ext2resize.sourceforge.net
|
http://ext2resize.sourceforge.net
|
||||||
|
|
||||||
useful links: http://www.zip.com.au/~akpm/linux/ext3/ext3-usage.html
|
useful links: http://www-106.ibm.com/developerworks/linux/library/l-fs7/
|
||||||
http://www-106.ibm.com/developerworks/linux/library/l-fs7/
|
|
||||||
http://www-106.ibm.com/developerworks/linux/library/l-fs8/
|
http://www-106.ibm.com/developerworks/linux/library/l-fs8/
|
||||||
|
|
|
@ -2,19 +2,24 @@
|
||||||
Ext4 Filesystem
|
Ext4 Filesystem
|
||||||
===============
|
===============
|
||||||
|
|
||||||
This is a development version of the ext4 filesystem, an advanced level
|
Ext4 is an an advanced level of the ext3 filesystem which incorporates
|
||||||
of the ext3 filesystem which incorporates scalability and reliability
|
scalability and reliability enhancements for supporting large filesystems
|
||||||
enhancements for supporting large filesystems (64 bit) in keeping with
|
(64 bit) in keeping with increasing disk capacities and state-of-the-art
|
||||||
increasing disk capacities and state-of-the-art feature requirements.
|
feature requirements.
|
||||||
|
|
||||||
Mailing list: linux-ext4@vger.kernel.org
|
Mailing list: linux-ext4@vger.kernel.org
|
||||||
|
Web site: http://ext4.wiki.kernel.org
|
||||||
|
|
||||||
|
|
||||||
1. Quick usage instructions:
|
1. Quick usage instructions:
|
||||||
===========================
|
===========================
|
||||||
|
|
||||||
|
Note: More extensive information for getting started with ext4 can be
|
||||||
|
found at the ext4 wiki site at the URL:
|
||||||
|
http://ext4.wiki.kernel.org/index.php/Ext4_Howto
|
||||||
|
|
||||||
- Compile and install the latest version of e2fsprogs (as of this
|
- Compile and install the latest version of e2fsprogs (as of this
|
||||||
writing version 1.41) from:
|
writing version 1.41.3) from:
|
||||||
|
|
||||||
http://sourceforge.net/project/showfiles.php?group_id=2406
|
http://sourceforge.net/project/showfiles.php?group_id=2406
|
||||||
|
|
||||||
|
@ -32,28 +37,26 @@ Mailing list: linux-ext4@vger.kernel.org
|
||||||
you will need to merge your changes with the version from e2fsprogs
|
you will need to merge your changes with the version from e2fsprogs
|
||||||
1.41.x.
|
1.41.x.
|
||||||
|
|
||||||
- Create a new filesystem using the ext4dev filesystem type:
|
- Create a new filesystem using the ext4 filesystem type:
|
||||||
|
|
||||||
# mke2fs -t ext4dev /dev/hda1
|
# mke2fs -t ext4 /dev/hda1
|
||||||
|
|
||||||
Or configure an existing ext3 filesystem to support extents and set
|
Or to configure an existing ext3 filesystem to support extents:
|
||||||
the test_fs flag to indicate that it's ok for an in-development
|
|
||||||
filesystem to touch this filesystem:
|
|
||||||
|
|
||||||
# tune2fs -O extents -E test_fs /dev/hda1
|
# tune2fs -O extents /dev/hda1
|
||||||
|
|
||||||
If the filesystem was created with 128 byte inodes, it can be
|
If the filesystem was created with 128 byte inodes, it can be
|
||||||
converted to use 256 byte for greater efficiency via:
|
converted to use 256 byte for greater efficiency via:
|
||||||
|
|
||||||
# tune2fs -I 256 /dev/hda1
|
# tune2fs -I 256 /dev/hda1
|
||||||
|
|
||||||
(Note: we currently do not have tools to convert an ext4dev
|
(Note: we currently do not have tools to convert an ext4
|
||||||
filesystem back to ext3; so please do not do try this on production
|
filesystem back to ext3; so please do not do try this on production
|
||||||
filesystems.)
|
filesystems.)
|
||||||
|
|
||||||
- Mounting:
|
- Mounting:
|
||||||
|
|
||||||
# mount -t ext4dev /dev/hda1 /wherever
|
# mount -t ext4 /dev/hda1 /wherever
|
||||||
|
|
||||||
- When comparing performance with other filesystems, remember that
|
- When comparing performance with other filesystems, remember that
|
||||||
ext3/4 by default offers higher data integrity guarantees than most.
|
ext3/4 by default offers higher data integrity guarantees than most.
|
||||||
|
@ -104,8 +107,8 @@ exist yet so I'm not sure they're in the near-term roadmap.
|
||||||
The big performance win will come with mballoc, delalloc and flex_bg
|
The big performance win will come with mballoc, delalloc and flex_bg
|
||||||
grouping of bitmaps and inode tables. Some test results available here:
|
grouping of bitmaps and inode tables. Some test results available here:
|
||||||
|
|
||||||
- http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html
|
- http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html
|
||||||
- http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
|
- http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html
|
||||||
|
|
||||||
3. Options
|
3. Options
|
||||||
==========
|
==========
|
||||||
|
@ -177,6 +180,11 @@ barrier=<0|1(*)> This enables/disables the use of write barriers in
|
||||||
your disks are battery-backed in one way or another,
|
your disks are battery-backed in one way or another,
|
||||||
disabling barriers may safely improve performance.
|
disabling barriers may safely improve performance.
|
||||||
|
|
||||||
|
inode_readahead=n This tuning parameter controls the maximum
|
||||||
|
number of inode table blocks that ext4's inode
|
||||||
|
table readahead algorithm will pre-read into
|
||||||
|
the buffer cache. The default value is 32 blocks.
|
||||||
|
|
||||||
orlov (*) This enables the new Orlov block allocator. It is
|
orlov (*) This enables the new Orlov block allocator. It is
|
||||||
enabled by default.
|
enabled by default.
|
||||||
|
|
||||||
|
@ -209,15 +217,17 @@ noreservation
|
||||||
bsddf (*) Make 'df' act like BSD.
|
bsddf (*) Make 'df' act like BSD.
|
||||||
minixdf Make 'df' act like Minix.
|
minixdf Make 'df' act like Minix.
|
||||||
|
|
||||||
check=none Don't do extra checking of bitmaps on mount.
|
|
||||||
nocheck
|
|
||||||
|
|
||||||
debug Extra debugging information is sent to syslog.
|
debug Extra debugging information is sent to syslog.
|
||||||
|
|
||||||
errors=remount-ro(*) Remount the filesystem read-only on an error.
|
errors=remount-ro(*) Remount the filesystem read-only on an error.
|
||||||
errors=continue Keep going on a filesystem error.
|
errors=continue Keep going on a filesystem error.
|
||||||
errors=panic Panic and halt the machine if an error occurs.
|
errors=panic Panic and halt the machine if an error occurs.
|
||||||
|
|
||||||
|
data_err=ignore(*) Just print an error message if an error occurs
|
||||||
|
in a file data buffer in ordered mode.
|
||||||
|
data_err=abort Abort the journal if an error occurs in a file
|
||||||
|
data buffer in ordered mode.
|
||||||
|
|
||||||
grpid Give objects the same group ID as their creator.
|
grpid Give objects the same group ID as their creator.
|
||||||
bsdgroups
|
bsdgroups
|
||||||
|
|
||||||
|
@ -243,8 +253,6 @@ nobh (a) cache disk block mapping information
|
||||||
"nobh" option tries to avoid associating buffer
|
"nobh" option tries to avoid associating buffer
|
||||||
heads (supported only for "writeback" mode).
|
heads (supported only for "writeback" mode).
|
||||||
|
|
||||||
mballoc (*) Use the multiple block allocator for block allocation
|
|
||||||
nomballoc disabled multiple block allocator for block allocation.
|
|
||||||
stripe=n Number of filesystem blocks that mballoc will try
|
stripe=n Number of filesystem blocks that mballoc will try
|
||||||
to use for allocation size and alignment. For RAID5/6
|
to use for allocation size and alignment. For RAID5/6
|
||||||
systems this should be the number of data
|
systems this should be the number of data
|
||||||
|
@ -252,6 +260,7 @@ stripe=n Number of filesystem blocks that mballoc will try
|
||||||
delalloc (*) Deferring block allocation until write-out time.
|
delalloc (*) Deferring block allocation until write-out time.
|
||||||
nodelalloc Disable delayed allocation. Blocks are allocation
|
nodelalloc Disable delayed allocation. Blocks are allocation
|
||||||
when data is copied from user to page cache.
|
when data is copied from user to page cache.
|
||||||
|
|
||||||
Data Mode
|
Data Mode
|
||||||
=========
|
=========
|
||||||
There are 3 different data modes:
|
There are 3 different data modes:
|
||||||
|
|
|
@ -0,0 +1,228 @@
|
||||||
|
============
|
||||||
|
Fiemap Ioctl
|
||||||
|
============
|
||||||
|
|
||||||
|
The fiemap ioctl is an efficient method for userspace to get file
|
||||||
|
extent mappings. Instead of block-by-block mapping (such as bmap), fiemap
|
||||||
|
returns a list of extents.
|
||||||
|
|
||||||
|
|
||||||
|
Request Basics
|
||||||
|
--------------
|
||||||
|
|
||||||
|
A fiemap request is encoded within struct fiemap:
|
||||||
|
|
||||||
|
struct fiemap {
|
||||||
|
__u64 fm_start; /* logical offset (inclusive) at
|
||||||
|
* which to start mapping (in) */
|
||||||
|
__u64 fm_length; /* logical length of mapping which
|
||||||
|
* userspace cares about (in) */
|
||||||
|
__u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
|
||||||
|
__u32 fm_mapped_extents; /* number of extents that were
|
||||||
|
* mapped (out) */
|
||||||
|
__u32 fm_extent_count; /* size of fm_extents array (in) */
|
||||||
|
__u32 fm_reserved;
|
||||||
|
struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
fm_start, and fm_length specify the logical range within the file
|
||||||
|
which the process would like mappings for. Extents returned mirror
|
||||||
|
those on disk - that is, the logical offset of the 1st returned extent
|
||||||
|
may start before fm_start, and the range covered by the last returned
|
||||||
|
extent may end after fm_length. All offsets and lengths are in bytes.
|
||||||
|
|
||||||
|
Certain flags to modify the way in which mappings are looked up can be
|
||||||
|
set in fm_flags. If the kernel doesn't understand some particular
|
||||||
|
flags, it will return EBADR and the contents of fm_flags will contain
|
||||||
|
the set of flags which caused the error. If the kernel is compatible
|
||||||
|
with all flags passed, the contents of fm_flags will be unmodified.
|
||||||
|
It is up to userspace to determine whether rejection of a particular
|
||||||
|
flag is fatal to it's operation. This scheme is intended to allow the
|
||||||
|
fiemap interface to grow in the future but without losing
|
||||||
|
compatibility with old software.
|
||||||
|
|
||||||
|
fm_extent_count specifies the number of elements in the fm_extents[] array
|
||||||
|
that can be used to return extents. If fm_extent_count is zero, then the
|
||||||
|
fm_extents[] array is ignored (no extents will be returned), and the
|
||||||
|
fm_mapped_extents count will hold the number of extents needed in
|
||||||
|
fm_extents[] to hold the file's current mapping. Note that there is
|
||||||
|
nothing to prevent the file from changing between calls to FIEMAP.
|
||||||
|
|
||||||
|
The following flags can be set in fm_flags:
|
||||||
|
|
||||||
|
* FIEMAP_FLAG_SYNC
|
||||||
|
If this flag is set, the kernel will sync the file before mapping extents.
|
||||||
|
|
||||||
|
* FIEMAP_FLAG_XATTR
|
||||||
|
If this flag is set, the extents returned will describe the inodes
|
||||||
|
extended attribute lookup tree, instead of it's data tree.
|
||||||
|
|
||||||
|
|
||||||
|
Extent Mapping
|
||||||
|
--------------
|
||||||
|
|
||||||
|
Extent information is returned within the embedded fm_extents array
|
||||||
|
which userspace must allocate along with the fiemap structure. The
|
||||||
|
number of elements in the fiemap_extents[] array should be passed via
|
||||||
|
fm_extent_count. The number of extents mapped by kernel will be
|
||||||
|
returned via fm_mapped_extents. If the number of fiemap_extents
|
||||||
|
allocated is less than would be required to map the requested range,
|
||||||
|
the maximum number of extents that can be mapped in the fm_extent[]
|
||||||
|
array will be returned and fm_mapped_extents will be equal to
|
||||||
|
fm_extent_count. In that case, the last extent in the array will not
|
||||||
|
complete the requested range and will not have the FIEMAP_EXTENT_LAST
|
||||||
|
flag set (see the next section on extent flags).
|
||||||
|
|
||||||
|
Each extent is described by a single fiemap_extent structure as
|
||||||
|
returned in fm_extents.
|
||||||
|
|
||||||
|
struct fiemap_extent {
|
||||||
|
__u64 fe_logical; /* logical offset in bytes for the start of
|
||||||
|
* the extent */
|
||||||
|
__u64 fe_physical; /* physical offset in bytes for the start
|
||||||
|
* of the extent */
|
||||||
|
__u64 fe_length; /* length in bytes for the extent */
|
||||||
|
__u64 fe_reserved64[2];
|
||||||
|
__u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
|
||||||
|
__u32 fe_reserved[3];
|
||||||
|
};
|
||||||
|
|
||||||
|
All offsets and lengths are in bytes and mirror those on disk. It is valid
|
||||||
|
for an extents logical offset to start before the request or it's logical
|
||||||
|
length to extend past the request. Unless FIEMAP_EXTENT_NOT_ALIGNED is
|
||||||
|
returned, fe_logical, fe_physical, and fe_length will be aligned to the
|
||||||
|
block size of the file system. With the exception of extents flagged as
|
||||||
|
FIEMAP_EXTENT_MERGED, adjacent extents will not be merged.
|
||||||
|
|
||||||
|
The fe_flags field contains flags which describe the extent returned.
|
||||||
|
A special flag, FIEMAP_EXTENT_LAST is always set on the last extent in
|
||||||
|
the file so that the process making fiemap calls can determine when no
|
||||||
|
more extents are available, without having to call the ioctl again.
|
||||||
|
|
||||||
|
Some flags are intentionally vague and will always be set in the
|
||||||
|
presence of other more specific flags. This way a program looking for
|
||||||
|
a general property does not have to know all existing and future flags
|
||||||
|
which imply that property.
|
||||||
|
|
||||||
|
For example, if FIEMAP_EXTENT_DATA_INLINE or FIEMAP_EXTENT_DATA_TAIL
|
||||||
|
are set, FIEMAP_EXTENT_NOT_ALIGNED will also be set. A program looking
|
||||||
|
for inline or tail-packed data can key on the specific flag. Software
|
||||||
|
which simply cares not to try operating on non-aligned extents
|
||||||
|
however, can just key on FIEMAP_EXTENT_NOT_ALIGNED, and not have to
|
||||||
|
worry about all present and future flags which might imply unaligned
|
||||||
|
data. Note that the opposite is not true - it would be valid for
|
||||||
|
FIEMAP_EXTENT_NOT_ALIGNED to appear alone.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_LAST
|
||||||
|
This is the last extent in the file. A mapping attempt past this
|
||||||
|
extent will return nothing.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_UNKNOWN
|
||||||
|
The location of this extent is currently unknown. This may indicate
|
||||||
|
the data is stored on an inaccessible volume or that no storage has
|
||||||
|
been allocated for the file yet.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_DELALLOC
|
||||||
|
- This will also set FIEMAP_EXTENT_UNKNOWN.
|
||||||
|
Delayed allocation - while there is data for this extent, it's
|
||||||
|
physical location has not been allocated yet.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_ENCODED
|
||||||
|
This extent does not consist of plain filesystem blocks but is
|
||||||
|
encoded (e.g. encrypted or compressed). Reading the data in this
|
||||||
|
extent via I/O to the block device will have undefined results.
|
||||||
|
|
||||||
|
Note that it is *always* undefined to try to update the data
|
||||||
|
in-place by writing to the indicated location without the
|
||||||
|
assistance of the filesystem, or to access the data using the
|
||||||
|
information returned by the FIEMAP interface while the filesystem
|
||||||
|
is mounted. In other words, user applications may only read the
|
||||||
|
extent data via I/O to the block device while the filesystem is
|
||||||
|
unmounted, and then only if the FIEMAP_EXTENT_ENCODED flag is
|
||||||
|
clear; user applications must not try reading or writing to the
|
||||||
|
filesystem via the block device under any other circumstances.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_DATA_ENCRYPTED
|
||||||
|
- This will also set FIEMAP_EXTENT_ENCODED
|
||||||
|
The data in this extent has been encrypted by the file system.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_NOT_ALIGNED
|
||||||
|
Extent offsets and length are not guaranteed to be block aligned.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_DATA_INLINE
|
||||||
|
This will also set FIEMAP_EXTENT_NOT_ALIGNED
|
||||||
|
Data is located within a meta data block.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_DATA_TAIL
|
||||||
|
This will also set FIEMAP_EXTENT_NOT_ALIGNED
|
||||||
|
Data is packed into a block with data from other files.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_UNWRITTEN
|
||||||
|
Unwritten extent - the extent is allocated but it's data has not been
|
||||||
|
initialized. This indicates the extent's data will be all zero if read
|
||||||
|
through the filesystem but the contents are undefined if read directly from
|
||||||
|
the device.
|
||||||
|
|
||||||
|
* FIEMAP_EXTENT_MERGED
|
||||||
|
This will be set when a file does not support extents, i.e., it uses a block
|
||||||
|
based addressing scheme. Since returning an extent for each block back to
|
||||||
|
userspace would be highly inefficient, the kernel will try to merge most
|
||||||
|
adjacent blocks into 'extents'.
|
||||||
|
|
||||||
|
|
||||||
|
VFS -> File System Implementation
|
||||||
|
---------------------------------
|
||||||
|
|
||||||
|
File systems wishing to support fiemap must implement a ->fiemap callback on
|
||||||
|
their inode_operations structure. The fs ->fiemap call is responsible for
|
||||||
|
defining it's set of supported fiemap flags, and calling a helper function on
|
||||||
|
each discovered extent:
|
||||||
|
|
||||||
|
struct inode_operations {
|
||||||
|
...
|
||||||
|
|
||||||
|
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
|
||||||
|
u64 len);
|
||||||
|
|
||||||
|
->fiemap is passed struct fiemap_extent_info which describes the
|
||||||
|
fiemap request:
|
||||||
|
|
||||||
|
struct fiemap_extent_info {
|
||||||
|
unsigned int fi_flags; /* Flags as passed from user */
|
||||||
|
unsigned int fi_extents_mapped; /* Number of mapped extents */
|
||||||
|
unsigned int fi_extents_max; /* Size of fiemap_extent array */
|
||||||
|
struct fiemap_extent *fi_extents_start; /* Start of fiemap_extent array */
|
||||||
|
};
|
||||||
|
|
||||||
|
It is intended that the file system should not need to access any of this
|
||||||
|
structure directly.
|
||||||
|
|
||||||
|
|
||||||
|
Flag checking should be done at the beginning of the ->fiemap callback via the
|
||||||
|
fiemap_check_flags() helper:
|
||||||
|
|
||||||
|
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
|
||||||
|
|
||||||
|
The struct fieinfo should be passed in as recieved from ioctl_fiemap(). The
|
||||||
|
set of fiemap flags which the fs understands should be passed via fs_flags. If
|
||||||
|
fiemap_check_flags finds invalid user flags, it will place the bad values in
|
||||||
|
fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from
|
||||||
|
fiemap_check_flags(), it should immediately exit, returning that error back to
|
||||||
|
ioctl_fiemap().
|
||||||
|
|
||||||
|
|
||||||
|
For each extent in the request range, the file system should call
|
||||||
|
the helper function, fiemap_fill_next_extent():
|
||||||
|
|
||||||
|
int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
|
||||||
|
u64 phys, u64 len, u32 flags, u32 dev);
|
||||||
|
|
||||||
|
fiemap_fill_next_extent() will use the passed values to populate the
|
||||||
|
next free extent in the fm_extents array. 'General' extent flags will
|
||||||
|
automatically be set from specific flags on behalf of the calling file
|
||||||
|
system so that the userspace API is not broken.
|
||||||
|
|
||||||
|
fiemap_fill_next_extent() returns 0 on success, and 1 when the
|
||||||
|
user-supplied fm_extents array is full. If an error is encountered
|
||||||
|
while copying the extent to user memory, -EFAULT will be returned.
|
|
@ -169,7 +169,7 @@ They depend on various facilities being available:
|
||||||
3.1) Booting from a floppy using syslinux
|
3.1) Booting from a floppy using syslinux
|
||||||
|
|
||||||
When building kernels, an easy way to create a boot floppy that uses
|
When building kernels, an easy way to create a boot floppy that uses
|
||||||
syslinux is to use the zdisk or bzdisk make targets which use
|
syslinux is to use the zdisk or bzdisk make targets which use zimage
|
||||||
and bzimage images respectively. Both targets accept the
|
and bzimage images respectively. Both targets accept the
|
||||||
FDARGS parameter which can be used to set the kernel command line.
|
FDARGS parameter which can be used to set the kernel command line.
|
||||||
|
|
||||||
|
|
|
@ -76,3 +76,9 @@ localalloc=8(*) Allows custom localalloc size in MB. If the value is too
|
||||||
large, the fs will silently revert it to the default.
|
large, the fs will silently revert it to the default.
|
||||||
Localalloc is not enabled for local mounts.
|
Localalloc is not enabled for local mounts.
|
||||||
localflocks This disables cluster aware flock.
|
localflocks This disables cluster aware flock.
|
||||||
|
inode64 Indicates that Ocfs2 is allowed to create inodes at
|
||||||
|
any location in the filesystem, including those which
|
||||||
|
will result in inode numbers occupying more than 32
|
||||||
|
bits of significance.
|
||||||
|
user_xattr (*) Enables Extended User Attributes.
|
||||||
|
nouser_xattr Disables Extended User Attributes.
|
||||||
|
|
|
@ -923,45 +923,44 @@ CPUs.
|
||||||
The "procs_blocked" line gives the number of processes currently blocked,
|
The "procs_blocked" line gives the number of processes currently blocked,
|
||||||
waiting for I/O to complete.
|
waiting for I/O to complete.
|
||||||
|
|
||||||
|
|
||||||
1.9 Ext4 file system parameters
|
1.9 Ext4 file system parameters
|
||||||
------------------------------
|
------------------------------
|
||||||
Ext4 file system have one directory per partition under /proc/fs/ext4/
|
|
||||||
# ls /proc/fs/ext4/hdc/
|
|
||||||
group_prealloc max_to_scan mb_groups mb_history min_to_scan order2_req
|
|
||||||
stats stream_req
|
|
||||||
|
|
||||||
mb_groups:
|
Information about mounted ext4 file systems can be found in
|
||||||
This file gives the details of multiblock allocator buddy cache of free blocks
|
/proc/fs/ext4. Each mounted filesystem will have a directory in
|
||||||
|
/proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
|
||||||
|
/proc/fs/ext4/dm-0). The files in each per-device directory are shown
|
||||||
|
in Table 1-10, below.
|
||||||
|
|
||||||
mb_history:
|
Table 1-10: Files in /proc/fs/ext4/<devname>
|
||||||
Multiblock allocation history.
|
..............................................................................
|
||||||
|
File Content
|
||||||
|
mb_groups details of multiblock allocator buddy cache of free blocks
|
||||||
|
mb_history multiblock allocation history
|
||||||
|
stats controls whether the multiblock allocator should start
|
||||||
|
collecting statistics, which are shown during the unmount
|
||||||
|
group_prealloc the multiblock allocator will round up allocation
|
||||||
|
requests to a multiple of this tuning parameter if the
|
||||||
|
stripe size is not set in the ext4 superblock
|
||||||
|
max_to_scan The maximum number of extents the multiblock allocator
|
||||||
|
will search to find the best extent
|
||||||
|
min_to_scan The minimum number of extents the multiblock allocator
|
||||||
|
will search to find the best extent
|
||||||
|
order2_req Tuning parameter which controls the minimum size for
|
||||||
|
requests (as a power of 2) where the buddy cache is
|
||||||
|
used
|
||||||
|
stream_req Files which have fewer blocks than this tunable
|
||||||
|
parameter will have their blocks allocated out of a
|
||||||
|
block group specific preallocation pool, so that small
|
||||||
|
files are packed closely together. Each large file
|
||||||
|
will have its blocks allocated out of its own unique
|
||||||
|
preallocation pool.
|
||||||
|
inode_readahead Tuning parameter which controls the maximum number of
|
||||||
|
inode table blocks that ext4's inode table readahead
|
||||||
|
algorithm will pre-read into the buffer cache
|
||||||
|
..............................................................................
|
||||||
|
|
||||||
stats:
|
|
||||||
This file indicate whether the multiblock allocator should start collecting
|
|
||||||
statistics. The statistics are shown during unmount
|
|
||||||
|
|
||||||
group_prealloc:
|
|
||||||
The multiblock allocator normalize the block allocation request to
|
|
||||||
group_prealloc filesystem blocks if we don't have strip value set.
|
|
||||||
The stripe value can be specified at mount time or during mke2fs.
|
|
||||||
|
|
||||||
max_to_scan:
|
|
||||||
How long multiblock allocator can look for a best extent (in found extents)
|
|
||||||
|
|
||||||
min_to_scan:
|
|
||||||
How long multiblock allocator must look for a best extent
|
|
||||||
|
|
||||||
order2_req:
|
|
||||||
Multiblock allocator use 2^N search using buddies only for requests greater
|
|
||||||
than or equal to order2_req. The request size is specfied in file system
|
|
||||||
blocks. A value of 2 indicate only if the requests are greater than or equal
|
|
||||||
to 4 blocks.
|
|
||||||
|
|
||||||
stream_req:
|
|
||||||
Files smaller than stream_req are served by the stream allocator, whose
|
|
||||||
purpose is to pack requests as close each to other as possible to
|
|
||||||
produce smooth I/O traffic. Avalue of 16 indicate that file smaller than 16
|
|
||||||
filesystem block size will use group based preallocation.
|
|
||||||
|
|
||||||
------------------------------------------------------------------------------
|
------------------------------------------------------------------------------
|
||||||
Summary
|
Summary
|
||||||
|
@ -1322,6 +1321,18 @@ debugging information is displayed on console.
|
||||||
NMI switch that most IA32 servers have fires unknown NMI up, for example.
|
NMI switch that most IA32 servers have fires unknown NMI up, for example.
|
||||||
If a system hangs up, try pressing the NMI switch.
|
If a system hangs up, try pressing the NMI switch.
|
||||||
|
|
||||||
|
panic_on_unrecovered_nmi
|
||||||
|
------------------------
|
||||||
|
|
||||||
|
The default Linux behaviour on an NMI of either memory or unknown is to continue
|
||||||
|
operation. For many environments such as scientific computing it is preferable
|
||||||
|
that the box is taken out and the error dealt with than an uncorrected
|
||||||
|
parity/ECC error get propogated.
|
||||||
|
|
||||||
|
A small number of systems do generate NMI's for bizarre random reasons such as
|
||||||
|
power management so the default is off. That sysctl works like the existing
|
||||||
|
panic controls already in that directory.
|
||||||
|
|
||||||
nmi_watchdog
|
nmi_watchdog
|
||||||
------------
|
------------
|
||||||
|
|
||||||
|
@ -1332,13 +1343,6 @@ determine whether or not they are still functioning properly.
|
||||||
Because the NMI watchdog shares registers with oprofile, by disabling the NMI
|
Because the NMI watchdog shares registers with oprofile, by disabling the NMI
|
||||||
watchdog, oprofile may have more registers to utilize.
|
watchdog, oprofile may have more registers to utilize.
|
||||||
|
|
||||||
maps_protect
|
|
||||||
------------
|
|
||||||
|
|
||||||
Enables/Disables the protection of the per-process proc entries "maps" and
|
|
||||||
"smaps". When enabled, the contents of these files are visible only to
|
|
||||||
readers that are allowed to ptrace() the given process.
|
|
||||||
|
|
||||||
msgmni
|
msgmni
|
||||||
------
|
------
|
||||||
|
|
||||||
|
@ -1380,15 +1384,18 @@ causes the kernel to prefer to reclaim dentries and inodes.
|
||||||
dirty_background_ratio
|
dirty_background_ratio
|
||||||
----------------------
|
----------------------
|
||||||
|
|
||||||
Contains, as a percentage of total system memory, the number of pages at which
|
Contains, as a percentage of the dirtyable system memory (free pages + mapped
|
||||||
the pdflush background writeback daemon will start writing out dirty data.
|
pages + file cache, not including locked pages and HugePages), the number of
|
||||||
|
pages at which the pdflush background writeback daemon will start writing out
|
||||||
|
dirty data.
|
||||||
|
|
||||||
dirty_ratio
|
dirty_ratio
|
||||||
-----------------
|
-----------------
|
||||||
|
|
||||||
Contains, as a percentage of total system memory, the number of pages at which
|
Contains, as a percentage of the dirtyable system memory (free pages + mapped
|
||||||
a process which is generating disk writes will itself start writing out dirty
|
pages + file cache, not including locked pages and HugePages), the number of
|
||||||
data.
|
pages at which a process which is generating disk writes will itself start
|
||||||
|
writing out dirty data.
|
||||||
|
|
||||||
dirty_writeback_centisecs
|
dirty_writeback_centisecs
|
||||||
-------------------------
|
-------------------------
|
||||||
|
@ -2408,24 +2415,29 @@ will be dumped when the <pid> process is dumped. coredump_filter is a bitmask
|
||||||
of memory types. If a bit of the bitmask is set, memory segments of the
|
of memory types. If a bit of the bitmask is set, memory segments of the
|
||||||
corresponding memory type are dumped, otherwise they are not dumped.
|
corresponding memory type are dumped, otherwise they are not dumped.
|
||||||
|
|
||||||
The following 4 memory types are supported:
|
The following 7 memory types are supported:
|
||||||
- (bit 0) anonymous private memory
|
- (bit 0) anonymous private memory
|
||||||
- (bit 1) anonymous shared memory
|
- (bit 1) anonymous shared memory
|
||||||
- (bit 2) file-backed private memory
|
- (bit 2) file-backed private memory
|
||||||
- (bit 3) file-backed shared memory
|
- (bit 3) file-backed shared memory
|
||||||
- (bit 4) ELF header pages in file-backed private memory areas (it is
|
- (bit 4) ELF header pages in file-backed private memory areas (it is
|
||||||
effective only if the bit 2 is cleared)
|
effective only if the bit 2 is cleared)
|
||||||
|
- (bit 5) hugetlb private memory
|
||||||
|
- (bit 6) hugetlb shared memory
|
||||||
|
|
||||||
Note that MMIO pages such as frame buffer are never dumped and vDSO pages
|
Note that MMIO pages such as frame buffer are never dumped and vDSO pages
|
||||||
are always dumped regardless of the bitmask status.
|
are always dumped regardless of the bitmask status.
|
||||||
|
|
||||||
Default value of coredump_filter is 0x3; this means all anonymous memory
|
Note bit 0-4 doesn't effect any hugetlb memory. hugetlb memory are only
|
||||||
segments are dumped.
|
effected by bit 5-6.
|
||||||
|
|
||||||
|
Default value of coredump_filter is 0x23; this means all anonymous memory
|
||||||
|
segments and hugetlb private memory are dumped.
|
||||||
|
|
||||||
If you don't want to dump all shared memory segments attached to pid 1234,
|
If you don't want to dump all shared memory segments attached to pid 1234,
|
||||||
write 1 to the process's proc file.
|
write 0x21 to the process's proc file.
|
||||||
|
|
||||||
$ echo 0x1 > /proc/1234/coredump_filter
|
$ echo 0x21 > /proc/1234/coredump_filter
|
||||||
|
|
||||||
When a new process is created, the process inherits the bitmask status from its
|
When a new process is created, the process inherits the bitmask status from its
|
||||||
parent. It is useful to set up coredump_filter before the program runs.
|
parent. It is useful to set up coredump_filter before the program runs.
|
||||||
|
|
|
@ -263,7 +263,7 @@ User Mode Linux, like so:
|
||||||
sleep(999999999);
|
sleep(999999999);
|
||||||
}
|
}
|
||||||
EOF
|
EOF
|
||||||
gcc -static hello2.c -o init
|
gcc -static hello.c -o init
|
||||||
echo init | cpio -o -H newc | gzip > test.cpio.gz
|
echo init | cpio -o -H newc | gzip > test.cpio.gz
|
||||||
# Testing external initramfs using the initrd loading mechanism.
|
# Testing external initramfs using the initrd loading mechanism.
|
||||||
qemu -kernel /boot/vmlinuz -initrd test.cpio.gz /dev/zero
|
qemu -kernel /boot/vmlinuz -initrd test.cpio.gz /dev/zero
|
||||||
|
|
|
@ -86,6 +86,15 @@ norm_unmount (*) commit on unmount; the journal is committed
|
||||||
fast_unmount do not commit on unmount; this option makes
|
fast_unmount do not commit on unmount; this option makes
|
||||||
unmount faster, but the next mount slower
|
unmount faster, but the next mount slower
|
||||||
because of the need to replay the journal.
|
because of the need to replay the journal.
|
||||||
|
bulk_read read more in one go to take advantage of flash
|
||||||
|
media that read faster sequentially
|
||||||
|
no_bulk_read (*) do not bulk-read
|
||||||
|
no_chk_data_crc skip checking of CRCs on data nodes in order to
|
||||||
|
improve read performance. Use this option only
|
||||||
|
if the flash media is highly reliable. The effect
|
||||||
|
of this option is that corruption of the contents
|
||||||
|
of a file can go unnoticed.
|
||||||
|
chk_data_crc (*) do not skip checking CRCs on data nodes
|
||||||
|
|
||||||
|
|
||||||
Quick usage instructions
|
Quick usage instructions
|
||||||
|
|
|
@ -240,6 +240,10 @@ signal, or (b) something wrongly believes it's safe to remove drivers
|
||||||
needed to manage a signal that's in active use. That is, requesting a
|
needed to manage a signal that's in active use. That is, requesting a
|
||||||
GPIO can serve as a kind of lock.
|
GPIO can serve as a kind of lock.
|
||||||
|
|
||||||
|
Some platforms may also use knowledge about what GPIOs are active for
|
||||||
|
power management, such as by powering down unused chip sectors and, more
|
||||||
|
easily, gating off unused clocks.
|
||||||
|
|
||||||
These two calls are optional because not not all current Linux platforms
|
These two calls are optional because not not all current Linux platforms
|
||||||
offer such functionality in their GPIO support; a valid implementation
|
offer such functionality in their GPIO support; a valid implementation
|
||||||
could return success for all gpio_request() calls. Unlike the other calls,
|
could return success for all gpio_request() calls. Unlike the other calls,
|
||||||
|
@ -264,7 +268,7 @@ map between them using calls like:
|
||||||
/* map GPIO numbers to IRQ numbers */
|
/* map GPIO numbers to IRQ numbers */
|
||||||
int gpio_to_irq(unsigned gpio);
|
int gpio_to_irq(unsigned gpio);
|
||||||
|
|
||||||
/* map IRQ numbers to GPIO numbers */
|
/* map IRQ numbers to GPIO numbers (avoid using this) */
|
||||||
int irq_to_gpio(unsigned irq);
|
int irq_to_gpio(unsigned irq);
|
||||||
|
|
||||||
Those return either the corresponding number in the other namespace, or
|
Those return either the corresponding number in the other namespace, or
|
||||||
|
@ -284,7 +288,8 @@ system wakeup capabilities.
|
||||||
|
|
||||||
Non-error values returned from irq_to_gpio() would most commonly be used
|
Non-error values returned from irq_to_gpio() would most commonly be used
|
||||||
with gpio_get_value(), for example to initialize or update driver state
|
with gpio_get_value(), for example to initialize or update driver state
|
||||||
when the IRQ is edge-triggered.
|
when the IRQ is edge-triggered. Note that some platforms don't support
|
||||||
|
this reverse mapping, so you should avoid using it.
|
||||||
|
|
||||||
|
|
||||||
Emulating Open Drain Signals
|
Emulating Open Drain Signals
|
||||||
|
|
|
@ -0,0 +1,76 @@
|
||||||
|
Kernel driver adt7470
|
||||||
|
=====================
|
||||||
|
|
||||||
|
Supported chips:
|
||||||
|
* Analog Devices ADT7470
|
||||||
|
Prefix: 'adt7470'
|
||||||
|
Addresses scanned: I2C 0x2C, 0x2E, 0x2F
|
||||||
|
Datasheet: Publicly available at the Analog Devices website
|
||||||
|
|
||||||
|
Author: Darrick J. Wong
|
||||||
|
|
||||||
|
Description
|
||||||
|
-----------
|
||||||
|
|
||||||
|
This driver implements support for the Analog Devices ADT7470 chip. There may
|
||||||
|
be other chips that implement this interface.
|
||||||
|
|
||||||
|
The ADT7470 uses the 2-wire interface compatible with the SMBus 2.0
|
||||||
|
specification. Using an analog to digital converter it measures up to ten (10)
|
||||||
|
external temperatures. It has four (4) 16-bit counters for measuring fan speed.
|
||||||
|
There are four (4) PWM outputs that can be used to control fan speed.
|
||||||
|
|
||||||
|
A sophisticated control system for the PWM outputs is designed into the ADT7470
|
||||||
|
that allows fan speed to be adjusted automatically based on any of the ten
|
||||||
|
temperature sensors. Each PWM output is individually adjustable and
|
||||||
|
programmable. Once configured, the ADT7470 will adjust the PWM outputs in
|
||||||
|
response to the measured temperatures with further host intervention. This
|
||||||
|
feature can also be disabled for manual control of the PWM's.
|
||||||
|
|
||||||
|
Each of the measured inputs (temperature, fan speed) has corresponding high/low
|
||||||
|
limit values. The ADT7470 will signal an ALARM if any measured value exceeds
|
||||||
|
either limit.
|
||||||
|
|
||||||
|
The ADT7470 DOES NOT sample all inputs continuously. A single pin on the
|
||||||
|
ADT7470 is connected to a multitude of thermal diodes, but the chip must be
|
||||||
|
instructed explicitly to read the multitude of diodes. If you want to use
|
||||||
|
automatic fan control mode, you must manually read any of the temperature
|
||||||
|
sensors or the fan control algorithm will not run. The chip WILL NOT DO THIS
|
||||||
|
AUTOMATICALLY; this must be done from userspace. This may be a bug in the chip
|
||||||
|
design, given that many other AD chips take care of this. The driver will not
|
||||||
|
read the registers more often than once every 5 seconds. Further,
|
||||||
|
configuration data is only read once per minute.
|
||||||
|
|
||||||
|
Special Features
|
||||||
|
----------------
|
||||||
|
|
||||||
|
The ADT7470 has a 8-bit ADC and is capable of measuring temperatures with 1
|
||||||
|
degC resolution.
|
||||||
|
|
||||||
|
The Analog Devices datasheet is very detailed and describes a procedure for
|
||||||
|
determining an optimal configuration for the automatic PWM control.
|
||||||
|
|
||||||
|
Configuration Notes
|
||||||
|
-------------------
|
||||||
|
|
||||||
|
Besides standard interfaces driver adds the following:
|
||||||
|
|
||||||
|
* PWM Control
|
||||||
|
|
||||||
|
* pwm#_auto_point1_pwm and pwm#_auto_point1_temp and
|
||||||
|
* pwm#_auto_point2_pwm and pwm#_auto_point2_temp -
|
||||||
|
|
||||||
|
point1: Set the pwm speed at a lower temperature bound.
|
||||||
|
point2: Set the pwm speed at a higher temperature bound.
|
||||||
|
|
||||||
|
The ADT7470 will scale the pwm between the lower and higher pwm speed when
|
||||||
|
the temperature is between the two temperature boundaries. PWM values range
|
||||||
|
from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the
|
||||||
|
temperature sensor associated with the PWM control exceeds
|
||||||
|
pwm#_auto_point2_temp.
|
||||||
|
|
||||||
|
Notes
|
||||||
|
-----
|
||||||
|
|
||||||
|
As stated above, the temperature inputs must be read periodically from
|
||||||
|
userspace in order for the automatic pwm algorithm to run.
|
|
@ -136,10 +136,10 @@ once-only alarms.
|
||||||
The IT87xx only updates its values each 1.5 seconds; reading it more often
|
The IT87xx only updates its values each 1.5 seconds; reading it more often
|
||||||
will do no harm, but will return 'old' values.
|
will do no harm, but will return 'old' values.
|
||||||
|
|
||||||
To change sensor N to a thermistor, 'echo 2 > tempN_type' where N is 1, 2,
|
To change sensor N to a thermistor, 'echo 4 > tempN_type' where N is 1, 2,
|
||||||
or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
|
or 3. To change sensor N to a thermal diode, 'echo 3 > tempN_type'.
|
||||||
Give 0 for unused sensor. Any other value is invalid. To configure this at
|
Give 0 for unused sensor. Any other value is invalid. To configure this at
|
||||||
startup, consult lm_sensors's /etc/sensors.conf. (2 = thermistor;
|
startup, consult lm_sensors's /etc/sensors.conf. (4 = thermistor;
|
||||||
3 = thermal diode)
|
3 = thermal diode)
|
||||||
|
|
||||||
|
|
||||||
|
|
|
@ -163,16 +163,6 @@ configured individually according to the following options.
|
||||||
* pwm#_auto_pwm_min - this specifies the PWM value for temp#_auto_temp_off
|
* pwm#_auto_pwm_min - this specifies the PWM value for temp#_auto_temp_off
|
||||||
temperature. (PWM value from 0 to 255)
|
temperature. (PWM value from 0 to 255)
|
||||||
|
|
||||||
* pwm#_auto_pwm_freq - select base frequency of PWM output. You can select
|
|
||||||
in range of 10.0 to 94.0 Hz in .1 Hz units.
|
|
||||||
(Values 100 to 940).
|
|
||||||
|
|
||||||
The pwm#_auto_pwm_freq can be set to one of the following 8 values. Setting the
|
|
||||||
frequency to a value not on this list, will result in the next higher frequency
|
|
||||||
being selected. The actual device frequency may vary slightly from this
|
|
||||||
specification as designed by the manufacturer. Consult the datasheet for more
|
|
||||||
details. (PWM Frequency values: 100, 150, 230, 300, 380, 470, 620, 940)
|
|
||||||
|
|
||||||
* pwm#_auto_pwm_minctl - this flags selects for temp#_auto_temp_off temperature
|
* pwm#_auto_pwm_minctl - this flags selects for temp#_auto_temp_off temperature
|
||||||
the bahaviour of fans. Write 1 to let fans spinning at
|
the bahaviour of fans. Write 1 to let fans spinning at
|
||||||
pwm#_auto_pwm_min or write 0 to let them off.
|
pwm#_auto_pwm_min or write 0 to let them off.
|
||||||
|
|
|
@ -65,11 +65,10 @@ The LM87 has four pins which can serve one of two possible functions,
|
||||||
depending on the hardware configuration.
|
depending on the hardware configuration.
|
||||||
|
|
||||||
Some functions share pins, so not all functions are available at the same
|
Some functions share pins, so not all functions are available at the same
|
||||||
time. Which are depends on the hardware setup. This driver assumes that
|
time. Which are depends on the hardware setup. This driver normally
|
||||||
the BIOS configured the chip correctly. In that respect, it differs from
|
assumes that firmware configured the chip correctly. Where this is not
|
||||||
the original driver (from lm_sensors for Linux 2.4), which would force the
|
the case, platform code must set the I2C client's platform_data to point
|
||||||
LM87 to an arbitrary, compile-time chosen mode, regardless of the actual
|
to a u8 value to be written to the channel register.
|
||||||
chipset wiring.
|
|
||||||
|
|
||||||
For reference, here is the list of exclusive functions:
|
For reference, here is the list of exclusive functions:
|
||||||
- in0+in5 (default) or temp3
|
- in0+in5 (default) or temp3
|
||||||
|
|
|
@ -11,7 +11,7 @@ Supported chips:
|
||||||
Prefix: 'lm99'
|
Prefix: 'lm99'
|
||||||
Addresses scanned: I2C 0x4c and 0x4d
|
Addresses scanned: I2C 0x4c and 0x4d
|
||||||
Datasheet: Publicly available at the National Semiconductor website
|
Datasheet: Publicly available at the National Semiconductor website
|
||||||
http://www.national.com/pf/LM/LM89.html
|
http://www.national.com/mpf/LM/LM89.html
|
||||||
* National Semiconductor LM99
|
* National Semiconductor LM99
|
||||||
Prefix: 'lm99'
|
Prefix: 'lm99'
|
||||||
Addresses scanned: I2C 0x4c and 0x4d
|
Addresses scanned: I2C 0x4c and 0x4d
|
||||||
|
@ -21,18 +21,32 @@ Supported chips:
|
||||||
Prefix: 'lm86'
|
Prefix: 'lm86'
|
||||||
Addresses scanned: I2C 0x4c
|
Addresses scanned: I2C 0x4c
|
||||||
Datasheet: Publicly available at the National Semiconductor website
|
Datasheet: Publicly available at the National Semiconductor website
|
||||||
http://www.national.com/pf/LM/LM86.html
|
http://www.national.com/mpf/LM/LM86.html
|
||||||
* Analog Devices ADM1032
|
* Analog Devices ADM1032
|
||||||
Prefix: 'adm1032'
|
Prefix: 'adm1032'
|
||||||
Addresses scanned: I2C 0x4c and 0x4d
|
Addresses scanned: I2C 0x4c and 0x4d
|
||||||
Datasheet: Publicly available at the Analog Devices website
|
Datasheet: Publicly available at the ON Semiconductor website
|
||||||
http://www.analog.com/en/prod/0,2877,ADM1032,00.html
|
http://www.onsemi.com/PowerSolutions/product.do?id=ADM1032
|
||||||
* Analog Devices ADT7461
|
* Analog Devices ADT7461
|
||||||
Prefix: 'adt7461'
|
Prefix: 'adt7461'
|
||||||
Addresses scanned: I2C 0x4c and 0x4d
|
Addresses scanned: I2C 0x4c and 0x4d
|
||||||
Datasheet: Publicly available at the Analog Devices website
|
Datasheet: Publicly available at the ON Semiconductor website
|
||||||
http://www.analog.com/en/prod/0,2877,ADT7461,00.html
|
http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461
|
||||||
Note: Only if in ADM1032 compatibility mode
|
* Maxim MAX6646
|
||||||
|
Prefix: 'max6646'
|
||||||
|
Addresses scanned: I2C 0x4d
|
||||||
|
Datasheet: Publicly available at the Maxim website
|
||||||
|
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
|
||||||
|
* Maxim MAX6647
|
||||||
|
Prefix: 'max6646'
|
||||||
|
Addresses scanned: I2C 0x4e
|
||||||
|
Datasheet: Publicly available at the Maxim website
|
||||||
|
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
|
||||||
|
* Maxim MAX6649
|
||||||
|
Prefix: 'max6646'
|
||||||
|
Addresses scanned: I2C 0x4c
|
||||||
|
Datasheet: Publicly available at the Maxim website
|
||||||
|
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
|
||||||
* Maxim MAX6657
|
* Maxim MAX6657
|
||||||
Prefix: 'max6657'
|
Prefix: 'max6657'
|
||||||
Addresses scanned: I2C 0x4c
|
Addresses scanned: I2C 0x4c
|
||||||
|
@ -70,25 +84,21 @@ Description
|
||||||
|
|
||||||
The LM90 is a digital temperature sensor. It senses its own temperature as
|
The LM90 is a digital temperature sensor. It senses its own temperature as
|
||||||
well as the temperature of up to one external diode. It is compatible
|
well as the temperature of up to one external diode. It is compatible
|
||||||
with many other devices such as the LM86, the LM89, the LM99, the ADM1032,
|
with many other devices, many of which are supported by this driver.
|
||||||
the MAX6657, MAX6658, MAX6659, MAX6680 and the MAX6681 all of which are
|
|
||||||
supported by this driver.
|
|
||||||
|
|
||||||
Note that there is no easy way to differentiate between the MAX6657,
|
Note that there is no easy way to differentiate between the MAX6657,
|
||||||
MAX6658 and MAX6659 variants. The extra address and features of the
|
MAX6658 and MAX6659 variants. The extra address and features of the
|
||||||
MAX6659 are not supported by this driver. The MAX6680 and MAX6681 only
|
MAX6659 are not supported by this driver. The MAX6680 and MAX6681 only
|
||||||
differ in their pinout, therefore they obviously can't (and don't need to)
|
differ in their pinout, therefore they obviously can't (and don't need to)
|
||||||
be distinguished. Additionally, the ADT7461 is supported if found in
|
be distinguished.
|
||||||
ADM1032 compatibility mode.
|
|
||||||
|
|
||||||
The specificity of this family of chipsets over the ADM1021/LM84
|
The specificity of this family of chipsets over the ADM1021/LM84
|
||||||
family is that it features critical limits with hysteresis, and an
|
family is that it features critical limits with hysteresis, and an
|
||||||
increased resolution of the remote temperature measurement.
|
increased resolution of the remote temperature measurement.
|
||||||
|
|
||||||
The different chipsets of the family are not strictly identical, although
|
The different chipsets of the family are not strictly identical, although
|
||||||
very similar. This driver doesn't handle any specific feature for now,
|
very similar. For reference, here comes a non-exhaustive list of specific
|
||||||
with the exception of SMBus PEC. For reference, here comes a non-exhaustive
|
features:
|
||||||
list of specific features:
|
|
||||||
|
|
||||||
LM90:
|
LM90:
|
||||||
* Filter and alert configuration register at 0xBF.
|
* Filter and alert configuration register at 0xBF.
|
||||||
|
@ -114,9 +124,11 @@ ADT7461:
|
||||||
* Lower resolution for remote temperature
|
* Lower resolution for remote temperature
|
||||||
|
|
||||||
MAX6657 and MAX6658:
|
MAX6657 and MAX6658:
|
||||||
|
* Better local resolution
|
||||||
* Remote sensor type selection
|
* Remote sensor type selection
|
||||||
|
|
||||||
MAX6659:
|
MAX6659:
|
||||||
|
* Better local resolution
|
||||||
* Selectable address
|
* Selectable address
|
||||||
* Second critical temperature limit
|
* Second critical temperature limit
|
||||||
* Remote sensor type selection
|
* Remote sensor type selection
|
||||||
|
@ -127,7 +139,8 @@ MAX6680 and MAX6681:
|
||||||
|
|
||||||
All temperature values are given in degrees Celsius. Resolution
|
All temperature values are given in degrees Celsius. Resolution
|
||||||
is 1.0 degree for the local temperature, 0.125 degree for the remote
|
is 1.0 degree for the local temperature, 0.125 degree for the remote
|
||||||
temperature.
|
temperature, except for the MAX6657, MAX6658 and MAX6659 which have a
|
||||||
|
resolution of 0.125 degree for both temperatures.
|
||||||
|
|
||||||
Each sensor has its own high and low limits, plus a critical limit.
|
Each sensor has its own high and low limits, plus a critical limit.
|
||||||
Additionally, there is a relative hysteresis value common to both critical
|
Additionally, there is a relative hysteresis value common to both critical
|
||||||
|
|
|
@ -5,12 +5,7 @@ Supported chips:
|
||||||
* National Semiconductor PC87360, PC87363, PC87364, PC87365 and PC87366
|
* National Semiconductor PC87360, PC87363, PC87364, PC87365 and PC87366
|
||||||
Prefixes: 'pc87360', 'pc87363', 'pc87364', 'pc87365', 'pc87366'
|
Prefixes: 'pc87360', 'pc87363', 'pc87364', 'pc87365', 'pc87366'
|
||||||
Addresses scanned: none, address read from Super I/O config space
|
Addresses scanned: none, address read from Super I/O config space
|
||||||
Datasheets:
|
Datasheets: No longer available
|
||||||
http://www.national.com/pf/PC/PC87360.html
|
|
||||||
http://www.national.com/pf/PC/PC87363.html
|
|
||||||
http://www.national.com/pf/PC/PC87364.html
|
|
||||||
http://www.national.com/pf/PC/PC87365.html
|
|
||||||
http://www.national.com/pf/PC/PC87366.html
|
|
||||||
|
|
||||||
Authors: Jean Delvare <khali@linux-fr.org>
|
Authors: Jean Delvare <khali@linux-fr.org>
|
||||||
|
|
||||||
|
|
|
@ -5,7 +5,7 @@ Supported chips:
|
||||||
* National Semiconductor PC87427
|
* National Semiconductor PC87427
|
||||||
Prefix: 'pc87427'
|
Prefix: 'pc87427'
|
||||||
Addresses scanned: none, address read from Super I/O config space
|
Addresses scanned: none, address read from Super I/O config space
|
||||||
Datasheet: http://www.winbond.com.tw/E-WINBONDHTM/partner/apc_007.html
|
Datasheet: No longer available
|
||||||
|
|
||||||
Author: Jean Delvare <khali@linux-fr.org>
|
Author: Jean Delvare <khali@linux-fr.org>
|
||||||
|
|
||||||
|
|
|
@ -353,7 +353,7 @@ in6=255
|
||||||
|
|
||||||
# PWM
|
# PWM
|
||||||
|
|
||||||
Additional info about PWM on the AS99127F (may apply to other Asus
|
* Additional info about PWM on the AS99127F (may apply to other Asus
|
||||||
chips as well) by Jean Delvare as of 2004-04-09:
|
chips as well) by Jean Delvare as of 2004-04-09:
|
||||||
|
|
||||||
AS99127F revision 2 seems to have two PWM registers at 0x59 and 0x5A,
|
AS99127F revision 2 seems to have two PWM registers at 0x59 and 0x5A,
|
||||||
|
@ -396,7 +396,7 @@ Please contact us if you can figure out how it is supposed to work. As
|
||||||
long as we don't know more, the w83781d driver doesn't handle PWM on
|
long as we don't know more, the w83781d driver doesn't handle PWM on
|
||||||
AS99127F chips at all.
|
AS99127F chips at all.
|
||||||
|
|
||||||
Additional info about PWM on the AS99127F rev.1 by Hector Martin:
|
* Additional info about PWM on the AS99127F rev.1 by Hector Martin:
|
||||||
|
|
||||||
I've been fiddling around with the (in)famous 0x59 register and
|
I've been fiddling around with the (in)famous 0x59 register and
|
||||||
found out the following values do work as a form of coarse pwm:
|
found out the following values do work as a form of coarse pwm:
|
||||||
|
@ -418,3 +418,36 @@ change.
|
||||||
My mobo is an ASUS A7V266-E. This behavior is similar to what I got
|
My mobo is an ASUS A7V266-E. This behavior is similar to what I got
|
||||||
with speedfan under Windows, where 0-15% would be off, 15-2x% (can't
|
with speedfan under Windows, where 0-15% would be off, 15-2x% (can't
|
||||||
remember the exact value) would be 70% and higher would be full on.
|
remember the exact value) would be 70% and higher would be full on.
|
||||||
|
|
||||||
|
* Additional info about PWM on the AS99127F rev.1 from lm-sensors
|
||||||
|
ticket #2350:
|
||||||
|
|
||||||
|
I conducted some experiment on Asus P3B-F motherboard with AS99127F
|
||||||
|
(Ver. 1).
|
||||||
|
|
||||||
|
I confirm that 0x59 register control the CPU_Fan Header on this
|
||||||
|
motherboard, and 0x5a register control PWR_Fan.
|
||||||
|
|
||||||
|
In order to reduce the dependency of specific fan, the measurement is
|
||||||
|
conducted with a digital scope without fan connected. I found out that
|
||||||
|
P3B-F actually output variable DC voltage on fan header center pin,
|
||||||
|
looks like PWM is filtered on this motherboard.
|
||||||
|
|
||||||
|
Here are some of measurements:
|
||||||
|
|
||||||
|
0x80 20 mV
|
||||||
|
0x81 20 mV
|
||||||
|
0x82 232 mV
|
||||||
|
0x83 1.2 V
|
||||||
|
0x84 2.31 V
|
||||||
|
0x85 3.44 V
|
||||||
|
0x86 4.62 V
|
||||||
|
0x87 5.81 V
|
||||||
|
0x88 7.01 V
|
||||||
|
9x89 8.22 V
|
||||||
|
0x8a 9.42 V
|
||||||
|
0x8b 10.6 V
|
||||||
|
0x8c 11.9 V
|
||||||
|
0x8d 12.4 V
|
||||||
|
0x8e 12.4 V
|
||||||
|
0x8f 12.4 V
|
||||||
|
|
|
@ -58,29 +58,35 @@ internal state that allows no clean access (Bank with ID register is not
|
||||||
currently selected). If you know the address of the chip, use a 'force'
|
currently selected). If you know the address of the chip, use a 'force'
|
||||||
parameter; this will put it into a more well-behaved state first.
|
parameter; this will put it into a more well-behaved state first.
|
||||||
|
|
||||||
The driver implements three temperature sensors, five fan rotation speed
|
The driver implements three temperature sensors, ten voltage sensors,
|
||||||
sensors, and ten voltage sensors.
|
five fan rotation speed sensors and manual PWM control of each fan.
|
||||||
|
|
||||||
Temperatures are measured in degrees Celsius and measurement resolution is 1
|
Temperatures are measured in degrees Celsius and measurement resolution is 1
|
||||||
degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
|
degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
|
||||||
the temperature gets higher than the Overtemperature Shutdown value; it stays
|
the temperature gets higher than the Overtemperature Shutdown value; it stays
|
||||||
on until the temperature falls below the Hysteresis value.
|
on until the temperature falls below the Hysteresis value.
|
||||||
|
|
||||||
|
Voltage sensors (also known as IN sensors) report their values in millivolts.
|
||||||
|
An alarm is triggered if the voltage has crossed a programmable minimum
|
||||||
|
or maximum limit.
|
||||||
|
|
||||||
Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
|
Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
|
||||||
triggered if the rotation speed has dropped below a programmable limit. Fan
|
triggered if the rotation speed has dropped below a programmable limit. Fan
|
||||||
readings can be divided by a programmable divider (1, 2, 4, 8, 16,
|
readings can be divided by a programmable divider (1, 2, 4, 8, 16,
|
||||||
32, 64 or 128 for all fans) to give the readings more range or accuracy.
|
32, 64 or 128 for all fans) to give the readings more range or accuracy.
|
||||||
|
|
||||||
Voltage sensors (also known as IN sensors) report their values in millivolts.
|
Each fan controlled is controlled by PWM. The PWM duty cycle can be read and
|
||||||
An alarm is triggered if the voltage has crossed a programmable minimum
|
set for each fan separately. Valid values range from 0 (stop) to 255 (full).
|
||||||
or maximum limit.
|
PWM 1-3 support Thermal Cruise mode, in which the PWMs are automatically
|
||||||
|
regulated to keep respectively temp 1-3 at a certain target temperature.
|
||||||
|
See below for the description of the sysfs-interface.
|
||||||
|
|
||||||
The w83791d has a global bit used to enable beeping from the speaker when an
|
The w83791d has a global bit used to enable beeping from the speaker when an
|
||||||
alarm is triggered as well as a bitmask to enable or disable the beep for
|
alarm is triggered as well as a bitmask to enable or disable the beep for
|
||||||
specific alarms. You need both the global beep enable bit and the
|
specific alarms. You need both the global beep enable bit and the
|
||||||
corresponding beep bit to be on for a triggered alarm to sound a beep.
|
corresponding beep bit to be on for a triggered alarm to sound a beep.
|
||||||
|
|
||||||
The sysfs interface to the gloabal enable is via the sysfs beep_enable file.
|
The sysfs interface to the global enable is via the sysfs beep_enable file.
|
||||||
This file is used for both legacy and new code.
|
This file is used for both legacy and new code.
|
||||||
|
|
||||||
The sysfs interface to the beep bitmask has migrated from the original legacy
|
The sysfs interface to the beep bitmask has migrated from the original legacy
|
||||||
|
@ -105,6 +111,27 @@ going forward.
|
||||||
The driver reads the hardware chip values at most once every three seconds.
|
The driver reads the hardware chip values at most once every three seconds.
|
||||||
User mode code requesting values more often will receive cached values.
|
User mode code requesting values more often will receive cached values.
|
||||||
|
|
||||||
|
/sys files
|
||||||
|
----------
|
||||||
|
The sysfs-interface is documented in the 'sysfs-interface' file. Only
|
||||||
|
chip-specific options are documented here.
|
||||||
|
|
||||||
|
pwm[1-3]_enable - this file controls mode of fan/temperature control for
|
||||||
|
fan 1-3. Fan/PWM 4-5 only support manual mode.
|
||||||
|
* 1 Manual mode
|
||||||
|
* 2 Thermal Cruise mode
|
||||||
|
* 3 Fan Speed Cruise mode (no further support)
|
||||||
|
|
||||||
|
temp[1-3]_target - defines the target temperature for Thermal Cruise mode.
|
||||||
|
Unit: millidegree Celsius
|
||||||
|
RW
|
||||||
|
|
||||||
|
temp[1-3]_tolerance - temperature tolerance for Thermal Cruise mode.
|
||||||
|
Specifies an interval around the target temperature
|
||||||
|
in which the fan speed is not changed.
|
||||||
|
Unit: millidegree Celsius
|
||||||
|
RW
|
||||||
|
|
||||||
Alarms bitmap vs. beep_mask bitmask
|
Alarms bitmap vs. beep_mask bitmask
|
||||||
------------------------------------
|
------------------------------------
|
||||||
For legacy code using the alarms and beep_mask files:
|
For legacy code using the alarms and beep_mask files:
|
||||||
|
@ -132,7 +159,3 @@ tart2 : alarms: 0x020000 beep_mask: 0x080000 <== mismatch
|
||||||
tart3 : alarms: 0x040000 beep_mask: 0x100000 <== mismatch
|
tart3 : alarms: 0x040000 beep_mask: 0x100000 <== mismatch
|
||||||
case_open : alarms: 0x001000 beep_mask: 0x001000
|
case_open : alarms: 0x001000 beep_mask: 0x001000
|
||||||
global_enable: alarms: -------- beep_mask: 0x800000 (modified via beep_enable)
|
global_enable: alarms: -------- beep_mask: 0x800000 (modified via beep_enable)
|
||||||
|
|
||||||
W83791D TODO:
|
|
||||||
---------------
|
|
||||||
Provide a patch for smart-fan control (still need appropriate motherboard/fans)
|
|
||||||
|
|
|
@ -16,6 +16,9 @@ Supported adapters:
|
||||||
* VIA Technologies, Inc. CX700
|
* VIA Technologies, Inc. CX700
|
||||||
Datasheet: available on request and under NDA from VIA
|
Datasheet: available on request and under NDA from VIA
|
||||||
|
|
||||||
|
* VIA Technologies, Inc. VX800/VX820
|
||||||
|
Datasheet: available on http://linux.via.com.tw
|
||||||
|
|
||||||
Authors:
|
Authors:
|
||||||
Kyösti Mälkki <kmalkki@cc.hut.fi>,
|
Kyösti Mälkki <kmalkki@cc.hut.fi>,
|
||||||
Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
Mark D. Studebaker <mdsxyz123@yahoo.com>,
|
||||||
|
@ -49,6 +52,7 @@ Your lspci -n listing must show one of these :
|
||||||
device 1106:3372 (VT8237S)
|
device 1106:3372 (VT8237S)
|
||||||
device 1106:3287 (VT8251)
|
device 1106:3287 (VT8251)
|
||||||
device 1106:8324 (CX700)
|
device 1106:8324 (CX700)
|
||||||
|
device 1106:8353 (VX800/VX820)
|
||||||
|
|
||||||
If none of these show up, you should look in the BIOS for settings like
|
If none of these show up, you should look in the BIOS for settings like
|
||||||
enable ACPI / SMBus or even USB.
|
enable ACPI / SMBus or even USB.
|
||||||
|
@ -57,5 +61,5 @@ Except for the oldest chips (VT82C596A/B, VT82C686A and most probably
|
||||||
VT8231), this driver supports I2C block transactions. Such transactions
|
VT8231), this driver supports I2C block transactions. Such transactions
|
||||||
are mainly useful to read from and write to EEPROMs.
|
are mainly useful to read from and write to EEPROMs.
|
||||||
|
|
||||||
The CX700 additionally appears to support SMBus PEC, although this driver
|
The CX700/VX800/VX820 additionally appears to support SMBus PEC, although
|
||||||
doesn't implement it yet.
|
this driver doesn't implement it yet.
|
||||||
|
|
|
@ -4,6 +4,10 @@ the /dev interface. You need to load module i2c-dev for this.
|
||||||
|
|
||||||
Each registered i2c adapter gets a number, counting from 0. You can
|
Each registered i2c adapter gets a number, counting from 0. You can
|
||||||
examine /sys/class/i2c-dev/ to see what number corresponds to which adapter.
|
examine /sys/class/i2c-dev/ to see what number corresponds to which adapter.
|
||||||
|
Alternatively, you can run "i2cdetect -l" to obtain a formated list of all
|
||||||
|
i2c adapters present on your system at a given time. i2cdetect is part of
|
||||||
|
the i2c-tools package.
|
||||||
|
|
||||||
I2C device files are character device files with major device number 89
|
I2C device files are character device files with major device number 89
|
||||||
and a minor device number corresponding to the number assigned as
|
and a minor device number corresponding to the number assigned as
|
||||||
explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
|
explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
|
||||||
|
@ -17,30 +21,34 @@ So let's say you want to access an i2c adapter from a C program. The
|
||||||
first thing to do is "#include <linux/i2c-dev.h>". Please note that
|
first thing to do is "#include <linux/i2c-dev.h>". Please note that
|
||||||
there are two files named "i2c-dev.h" out there, one is distributed
|
there are two files named "i2c-dev.h" out there, one is distributed
|
||||||
with the Linux kernel and is meant to be included from kernel
|
with the Linux kernel and is meant to be included from kernel
|
||||||
driver code, the other one is distributed with lm_sensors and is
|
driver code, the other one is distributed with i2c-tools and is
|
||||||
meant to be included from user-space programs. You obviously want
|
meant to be included from user-space programs. You obviously want
|
||||||
the second one here.
|
the second one here.
|
||||||
|
|
||||||
Now, you have to decide which adapter you want to access. You should
|
Now, you have to decide which adapter you want to access. You should
|
||||||
inspect /sys/class/i2c-dev/ to decide this. Adapter numbers are assigned
|
inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this.
|
||||||
somewhat dynamically, so you can not even assume /dev/i2c-0 is the
|
Adapter numbers are assigned somewhat dynamically, so you can not
|
||||||
first adapter.
|
assume much about them. They can even change from one boot to the next.
|
||||||
|
|
||||||
Next thing, open the device file, as follows:
|
Next thing, open the device file, as follows:
|
||||||
|
|
||||||
int file;
|
int file;
|
||||||
int adapter_nr = 2; /* probably dynamically determined */
|
int adapter_nr = 2; /* probably dynamically determined */
|
||||||
char filename[20];
|
char filename[20];
|
||||||
|
|
||||||
sprintf(filename,"/dev/i2c-%d",adapter_nr);
|
snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
|
||||||
if ((file = open(filename,O_RDWR)) < 0) {
|
file = open(filename, O_RDWR);
|
||||||
|
if (file < 0) {
|
||||||
/* ERROR HANDLING; you can check errno to see what went wrong */
|
/* ERROR HANDLING; you can check errno to see what went wrong */
|
||||||
exit(1);
|
exit(1);
|
||||||
}
|
}
|
||||||
|
|
||||||
When you have opened the device, you must specify with what device
|
When you have opened the device, you must specify with what device
|
||||||
address you want to communicate:
|
address you want to communicate:
|
||||||
|
|
||||||
int addr = 0x40; /* The I2C address */
|
int addr = 0x40; /* The I2C address */
|
||||||
if (ioctl(file,I2C_SLAVE,addr) < 0) {
|
|
||||||
|
if (ioctl(file, I2C_SLAVE, addr) < 0) {
|
||||||
/* ERROR HANDLING; you can check errno to see what went wrong */
|
/* ERROR HANDLING; you can check errno to see what went wrong */
|
||||||
exit(1);
|
exit(1);
|
||||||
}
|
}
|
||||||
|
@ -48,31 +56,41 @@ address you want to communicate:
|
||||||
Well, you are all set up now. You can now use SMBus commands or plain
|
Well, you are all set up now. You can now use SMBus commands or plain
|
||||||
I2C to communicate with your device. SMBus commands are preferred if
|
I2C to communicate with your device. SMBus commands are preferred if
|
||||||
the device supports them. Both are illustrated below.
|
the device supports them. Both are illustrated below.
|
||||||
|
|
||||||
__u8 register = 0x10; /* Device register to access */
|
__u8 register = 0x10; /* Device register to access */
|
||||||
__s32 res;
|
__s32 res;
|
||||||
char buf[10];
|
char buf[10];
|
||||||
|
|
||||||
/* Using SMBus commands */
|
/* Using SMBus commands */
|
||||||
res = i2c_smbus_read_word_data(file,register);
|
res = i2c_smbus_read_word_data(file, register);
|
||||||
if (res < 0) {
|
if (res < 0) {
|
||||||
/* ERROR HANDLING: i2c transaction failed */
|
/* ERROR HANDLING: i2c transaction failed */
|
||||||
} else {
|
} else {
|
||||||
/* res contains the read word */
|
/* res contains the read word */
|
||||||
}
|
}
|
||||||
|
|
||||||
/* Using I2C Write, equivalent of
|
/* Using I2C Write, equivalent of
|
||||||
i2c_smbus_write_word_data(file,register,0x6543) */
|
i2c_smbus_write_word_data(file, register, 0x6543) */
|
||||||
buf[0] = register;
|
buf[0] = register;
|
||||||
buf[1] = 0x43;
|
buf[1] = 0x43;
|
||||||
buf[2] = 0x65;
|
buf[2] = 0x65;
|
||||||
if ( write(file,buf,3) != 3) {
|
if (write(file, buf, 3) ! =3) {
|
||||||
/* ERROR HANDLING: i2c transaction failed */
|
/* ERROR HANDLING: i2c transaction failed */
|
||||||
}
|
}
|
||||||
|
|
||||||
/* Using I2C Read, equivalent of i2c_smbus_read_byte(file) */
|
/* Using I2C Read, equivalent of i2c_smbus_read_byte(file) */
|
||||||
if (read(file,buf,1) != 1) {
|
if (read(file, buf, 1) != 1) {
|
||||||
/* ERROR HANDLING: i2c transaction failed */
|
/* ERROR HANDLING: i2c transaction failed */
|
||||||
} else {
|
} else {
|
||||||
/* buf[0] contains the read byte */
|
/* buf[0] contains the read byte */
|
||||||
}
|
}
|
||||||
|
|
||||||
|
Note that only a subset of the I2C and SMBus protocols can be achieved by
|
||||||
|
the means of read() and write() calls. In particular, so-called combined
|
||||||
|
transactions (mixing read and write messages in the same transaction)
|
||||||
|
aren't supported. For this reason, this interface is almost never used by
|
||||||
|
user-space programs.
|
||||||
|
|
||||||
IMPORTANT: because of the use of inline functions, you *have* to use
|
IMPORTANT: because of the use of inline functions, you *have* to use
|
||||||
'-O' or some variation when you compile your program!
|
'-O' or some variation when you compile your program!
|
||||||
|
|
||||||
|
@ -80,31 +98,29 @@ IMPORTANT: because of the use of inline functions, you *have* to use
|
||||||
Full interface description
|
Full interface description
|
||||||
==========================
|
==========================
|
||||||
|
|
||||||
The following IOCTLs are defined and fully supported
|
The following IOCTLs are defined:
|
||||||
(see also i2c-dev.h):
|
|
||||||
|
|
||||||
ioctl(file,I2C_SLAVE,long addr)
|
ioctl(file, I2C_SLAVE, long addr)
|
||||||
Change slave address. The address is passed in the 7 lower bits of the
|
Change slave address. The address is passed in the 7 lower bits of the
|
||||||
argument (except for 10 bit addresses, passed in the 10 lower bits in this
|
argument (except for 10 bit addresses, passed in the 10 lower bits in this
|
||||||
case).
|
case).
|
||||||
|
|
||||||
ioctl(file,I2C_TENBIT,long select)
|
ioctl(file, I2C_TENBIT, long select)
|
||||||
Selects ten bit addresses if select not equals 0, selects normal 7 bit
|
Selects ten bit addresses if select not equals 0, selects normal 7 bit
|
||||||
addresses if select equals 0. Default 0. This request is only valid
|
addresses if select equals 0. Default 0. This request is only valid
|
||||||
if the adapter has I2C_FUNC_10BIT_ADDR.
|
if the adapter has I2C_FUNC_10BIT_ADDR.
|
||||||
|
|
||||||
ioctl(file,I2C_PEC,long select)
|
ioctl(file, I2C_PEC, long select)
|
||||||
Selects SMBus PEC (packet error checking) generation and verification
|
Selects SMBus PEC (packet error checking) generation and verification
|
||||||
if select not equals 0, disables if select equals 0. Default 0.
|
if select not equals 0, disables if select equals 0. Default 0.
|
||||||
Used only for SMBus transactions. This request only has an effect if the
|
Used only for SMBus transactions. This request only has an effect if the
|
||||||
the adapter has I2C_FUNC_SMBUS_PEC; it is still safe if not, it just
|
the adapter has I2C_FUNC_SMBUS_PEC; it is still safe if not, it just
|
||||||
doesn't have any effect.
|
doesn't have any effect.
|
||||||
|
|
||||||
ioctl(file,I2C_FUNCS,unsigned long *funcs)
|
ioctl(file, I2C_FUNCS, unsigned long *funcs)
|
||||||
Gets the adapter functionality and puts it in *funcs.
|
Gets the adapter functionality and puts it in *funcs.
|
||||||
|
|
||||||
ioctl(file,I2C_RDWR,struct i2c_rdwr_ioctl_data *msgset)
|
ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)
|
||||||
|
|
||||||
Do combined read/write transaction without stop in between.
|
Do combined read/write transaction without stop in between.
|
||||||
Only valid if the adapter has I2C_FUNC_I2C. The argument is
|
Only valid if the adapter has I2C_FUNC_I2C. The argument is
|
||||||
a pointer to a
|
a pointer to a
|
||||||
|
@ -120,10 +136,9 @@ ioctl(file,I2C_RDWR,struct i2c_rdwr_ioctl_data *msgset)
|
||||||
The slave address and whether to use ten bit address mode has to be
|
The slave address and whether to use ten bit address mode has to be
|
||||||
set in each message, overriding the values set with the above ioctl's.
|
set in each message, overriding the values set with the above ioctl's.
|
||||||
|
|
||||||
|
ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)
|
||||||
Other values are NOT supported at this moment, except for I2C_SMBUS,
|
Not meant to be called directly; instead, use the access functions
|
||||||
which you should never directly call; instead, use the access functions
|
below.
|
||||||
below.
|
|
||||||
|
|
||||||
You can do plain i2c transactions by using read(2) and write(2) calls.
|
You can do plain i2c transactions by using read(2) and write(2) calls.
|
||||||
You do not need to pass the address byte; instead, set it through
|
You do not need to pass the address byte; instead, set it through
|
||||||
|
@ -148,7 +163,52 @@ what happened. The 'write' transactions return 0 on success; the
|
||||||
returns the number of values read. The block buffers need not be longer
|
returns the number of values read. The block buffers need not be longer
|
||||||
than 32 bytes.
|
than 32 bytes.
|
||||||
|
|
||||||
The above functions are all macros, that resolve to calls to the
|
The above functions are all inline functions, that resolve to calls to
|
||||||
i2c_smbus_access function, that on its turn calls a specific ioctl
|
the i2c_smbus_access function, that on its turn calls a specific ioctl
|
||||||
with the data in a specific format. Read the source code if you
|
with the data in a specific format. Read the source code if you
|
||||||
want to know what happens behind the screens.
|
want to know what happens behind the screens.
|
||||||
|
|
||||||
|
|
||||||
|
Implementation details
|
||||||
|
======================
|
||||||
|
|
||||||
|
For the interested, here's the code flow which happens inside the kernel
|
||||||
|
when you use the /dev interface to I2C:
|
||||||
|
|
||||||
|
1* Your program opens /dev/i2c-N and calls ioctl() on it, as described in
|
||||||
|
section "C example" above.
|
||||||
|
|
||||||
|
2* These open() and ioctl() calls are handled by the i2c-dev kernel
|
||||||
|
driver: see i2c-dev.c:i2cdev_open() and i2c-dev.c:i2cdev_ioctl(),
|
||||||
|
respectively. You can think of i2c-dev as a generic I2C chip driver
|
||||||
|
that can be programmed from user-space.
|
||||||
|
|
||||||
|
3* Some ioctl() calls are for administrative tasks and are handled by
|
||||||
|
i2c-dev directly. Examples include I2C_SLAVE (set the address of the
|
||||||
|
device you want to access) and I2C_PEC (enable or disable SMBus error
|
||||||
|
checking on future transactions.)
|
||||||
|
|
||||||
|
4* Other ioctl() calls are converted to in-kernel function calls by
|
||||||
|
i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
|
||||||
|
functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
|
||||||
|
performs an SMBus transaction using i2c-core.c:i2c_smbus_xfer().
|
||||||
|
|
||||||
|
The i2c-dev driver is responsible for checking all the parameters that
|
||||||
|
come from user-space for validity. After this point, there is no
|
||||||
|
difference between these calls that came from user-space through i2c-dev
|
||||||
|
and calls that would have been performed by kernel I2C chip drivers
|
||||||
|
directly. This means that I2C bus drivers don't need to implement
|
||||||
|
anything special to support access from user-space.
|
||||||
|
|
||||||
|
5* These i2c-core.c/i2c.h functions are wrappers to the actual
|
||||||
|
implementation of your I2C bus driver. Each adapter must declare
|
||||||
|
callback functions implementing these standard calls.
|
||||||
|
i2c.h:i2c_get_functionality() calls i2c_adapter.algo->functionality(),
|
||||||
|
while i2c-core.c:i2c_smbus_xfer() calls either
|
||||||
|
adapter.algo->smbus_xfer() if it is implemented, or if not,
|
||||||
|
i2c-core.c:i2c_smbus_xfer_emulated() which in turn calls
|
||||||
|
i2c_adapter.algo->master_xfer().
|
||||||
|
|
||||||
|
After your I2C bus driver has processed these requests, execution runs
|
||||||
|
up the call chain, with almost no processing done, except by i2c-dev to
|
||||||
|
package the returned data, if any, in suitable format for the ioctl.
|
||||||
|
|
|
@ -109,8 +109,8 @@ specified through the Comm byte.
|
||||||
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P
|
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P
|
||||||
|
|
||||||
|
|
||||||
SMBus Process Call
|
SMBus Process Call: i2c_smbus_process_call()
|
||||||
==================
|
=============================================
|
||||||
|
|
||||||
This command selects a device register (through the Comm byte), sends
|
This command selects a device register (through the Comm byte), sends
|
||||||
16 bits of data to it, and reads 16 bits of data in return.
|
16 bits of data to it, and reads 16 bits of data in return.
|
||||||
|
|
|
@ -606,6 +606,8 @@ SMBus communication
|
||||||
extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
|
extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
|
||||||
extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
|
extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
|
||||||
u8 command, u16 value);
|
u8 command, u16 value);
|
||||||
|
extern s32 i2c_smbus_process_call(struct i2c_client *client,
|
||||||
|
u8 command, u16 value);
|
||||||
extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
|
extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
|
||||||
u8 command, u8 *values);
|
u8 command, u8 *values);
|
||||||
extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
|
extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
|
||||||
|
@ -621,8 +623,6 @@ These ones were removed from i2c-core because they had no users, but could
|
||||||
be added back later if needed:
|
be added back later if needed:
|
||||||
|
|
||||||
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
|
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
|
||||||
extern s32 i2c_smbus_process_call(struct i2c_client * client,
|
|
||||||
u8 command, u16 value);
|
|
||||||
extern s32 i2c_smbus_block_process_call(struct i2c_client *client,
|
extern s32 i2c_smbus_block_process_call(struct i2c_client *client,
|
||||||
u8 command, u8 length,
|
u8 command, u8 length,
|
||||||
u8 *values)
|
u8 *values)
|
||||||
|
|
|
@ -1,7 +1,8 @@
|
||||||
Currently, kvm module in EXPERIMENTAL stage on IA64. This means that
|
Currently, kvm module is in EXPERIMENTAL stage on IA64. This means that
|
||||||
interfaces are not stable enough to use. So, plase had better don't run
|
interfaces are not stable enough to use. So, please don't run critical
|
||||||
critical applications in virtual machine. We will try our best to make it
|
applications in virtual machine.
|
||||||
strong in future versions!
|
We will try our best to improve it in future versions!
|
||||||
|
|
||||||
Guide: How to boot up guests on kvm/ia64
|
Guide: How to boot up guests on kvm/ia64
|
||||||
|
|
||||||
This guide is to describe how to enable kvm support for IA-64 systems.
|
This guide is to describe how to enable kvm support for IA-64 systems.
|
||||||
|
|
|
@ -92,6 +92,7 @@ Code Seq# Include File Comments
|
||||||
'J' 00-1F drivers/scsi/gdth_ioctl.h
|
'J' 00-1F drivers/scsi/gdth_ioctl.h
|
||||||
'K' all linux/kd.h
|
'K' all linux/kd.h
|
||||||
'L' 00-1F linux/loop.h
|
'L' 00-1F linux/loop.h
|
||||||
|
'L' 20-2F driver/usb/misc/vstusb.h
|
||||||
'L' E0-FF linux/ppdd.h encrypted disk device driver
|
'L' E0-FF linux/ppdd.h encrypted disk device driver
|
||||||
<http://linux01.gwdg.de/~alatham/ppdd.html>
|
<http://linux01.gwdg.de/~alatham/ppdd.html>
|
||||||
'M' all linux/soundcard.h
|
'M' all linux/soundcard.h
|
||||||
|
@ -110,6 +111,8 @@ Code Seq# Include File Comments
|
||||||
'W' 00-1F linux/wanrouter.h conflict!
|
'W' 00-1F linux/wanrouter.h conflict!
|
||||||
'X' all linux/xfs_fs.h
|
'X' all linux/xfs_fs.h
|
||||||
'Y' all linux/cyclades.h
|
'Y' all linux/cyclades.h
|
||||||
|
'[' 00-07 linux/usb/usbtmc.h USB Test and Measurement Devices
|
||||||
|
<mailto:gregkh@suse.de>
|
||||||
'a' all ATM on linux
|
'a' all ATM on linux
|
||||||
<http://lrcwww.epfl.ch/linux-atm/magic.html>
|
<http://lrcwww.epfl.ch/linux-atm/magic.html>
|
||||||
'b' 00-FF bit3 vme host bridge
|
'b' 00-FF bit3 vme host bridge
|
||||||
|
|
|
@ -168,10 +168,10 @@ if ($#ARGV < 0) {
|
||||||
mkdir $ARGV[0],0777;
|
mkdir $ARGV[0],0777;
|
||||||
$state = 0;
|
$state = 0;
|
||||||
while (<STDIN>) {
|
while (<STDIN>) {
|
||||||
if (/^\.TH \"[^\"]*\" 4 \"([^\"]*)\"/) {
|
if (/^\.TH \"[^\"]*\" 9 \"([^\"]*)\"/) {
|
||||||
if ($state == 1) { close OUT }
|
if ($state == 1) { close OUT }
|
||||||
$state = 1;
|
$state = 1;
|
||||||
$fn = "$ARGV[0]/$1.4";
|
$fn = "$ARGV[0]/$1.9";
|
||||||
print STDERR "Creating $fn\n";
|
print STDERR "Creating $fn\n";
|
||||||
open OUT, ">$fn" or die "can't open $fn: $!\n";
|
open OUT, ">$fn" or die "can't open $fn: $!\n";
|
||||||
print OUT $_;
|
print OUT $_;
|
||||||
|
|
|
@ -101,6 +101,7 @@ parameter is applicable:
|
||||||
X86-64 X86-64 architecture is enabled.
|
X86-64 X86-64 architecture is enabled.
|
||||||
More X86-64 boot options can be found in
|
More X86-64 boot options can be found in
|
||||||
Documentation/x86_64/boot-options.txt .
|
Documentation/x86_64/boot-options.txt .
|
||||||
|
X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
|
||||||
|
|
||||||
In addition, the following text indicates that the option:
|
In addition, the following text indicates that the option:
|
||||||
|
|
||||||
|
@ -311,6 +312,11 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
isolate - enable device isolation (each device, as far
|
isolate - enable device isolation (each device, as far
|
||||||
as possible, will get its own protection
|
as possible, will get its own protection
|
||||||
domain)
|
domain)
|
||||||
|
fullflush - enable flushing of IO/TLB entries when
|
||||||
|
they are unmapped. Otherwise they are
|
||||||
|
flushed before they will be reused, which
|
||||||
|
is a lot of faster
|
||||||
|
|
||||||
amd_iommu_size= [HW,X86-64]
|
amd_iommu_size= [HW,X86-64]
|
||||||
Define the size of the aperture for the AMD IOMMU
|
Define the size of the aperture for the AMD IOMMU
|
||||||
driver. Possible values are:
|
driver. Possible values are:
|
||||||
|
@ -490,12 +496,6 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
Range: 0 - 8192
|
Range: 0 - 8192
|
||||||
Default: 64
|
Default: 64
|
||||||
|
|
||||||
disable_8254_timer
|
|
||||||
enable_8254_timer
|
|
||||||
[IA32/X86_64] Disable/Enable interrupt 0 timer routing
|
|
||||||
over the 8254 in addition to over the IO-APIC. The
|
|
||||||
kernel tries to set a sensible default.
|
|
||||||
|
|
||||||
hpet= [X86-32,HPET] option to control HPET usage
|
hpet= [X86-32,HPET] option to control HPET usage
|
||||||
Format: { enable (default) | disable | force }
|
Format: { enable (default) | disable | force }
|
||||||
disable: disable HPET and use PIT instead
|
disable: disable HPET and use PIT instead
|
||||||
|
@ -686,11 +686,12 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
|
earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
|
||||||
earlyprintk=vga
|
earlyprintk=vga
|
||||||
earlyprintk=serial[,ttySn[,baudrate]]
|
earlyprintk=serial[,ttySn[,baudrate]]
|
||||||
|
earlyprintk=dbgp
|
||||||
|
|
||||||
Append ",keep" to not disable it when the real console
|
Append ",keep" to not disable it when the real console
|
||||||
takes over.
|
takes over.
|
||||||
|
|
||||||
Only vga or serial at a time, not both.
|
Only vga or serial or usb debug port at a time.
|
||||||
|
|
||||||
Currently only ttyS0 and ttyS1 are supported.
|
Currently only ttyS0 and ttyS1 are supported.
|
||||||
|
|
||||||
|
@ -717,7 +718,7 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
See Documentation/block/as-iosched.txt and
|
See Documentation/block/as-iosched.txt and
|
||||||
Documentation/block/deadline-iosched.txt for details.
|
Documentation/block/deadline-iosched.txt for details.
|
||||||
|
|
||||||
elfcorehdr= [X86-32, X86_64]
|
elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
|
||||||
Specifies physical address of start of kernel core
|
Specifies physical address of start of kernel core
|
||||||
image elf header. Generally kexec loader will
|
image elf header. Generally kexec loader will
|
||||||
pass this option to capture kernel.
|
pass this option to capture kernel.
|
||||||
|
@ -823,6 +824,9 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
Defaults to the default architecture's huge page size
|
Defaults to the default architecture's huge page size
|
||||||
if not specified.
|
if not specified.
|
||||||
|
|
||||||
|
hlt [BUGS=ARM,SH]
|
||||||
|
|
||||||
|
i8042.debug [HW] Toggle i8042 debug mode
|
||||||
i8042.direct [HW] Put keyboard port into non-translated mode
|
i8042.direct [HW] Put keyboard port into non-translated mode
|
||||||
i8042.dumbkbd [HW] Pretend that controller can only read data from
|
i8042.dumbkbd [HW] Pretend that controller can only read data from
|
||||||
keyboard and cannot control its state
|
keyboard and cannot control its state
|
||||||
|
@ -1047,6 +1051,10 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
(only serial suported for now)
|
(only serial suported for now)
|
||||||
Format: <serial_device>[,baud]
|
Format: <serial_device>[,baud]
|
||||||
|
|
||||||
|
kmac= [MIPS] korina ethernet MAC address.
|
||||||
|
Configure the RouterBoard 532 series on-chip
|
||||||
|
Ethernet adapter MAC address.
|
||||||
|
|
||||||
l2cr= [PPC]
|
l2cr= [PPC]
|
||||||
|
|
||||||
l3cr= [PPC]
|
l3cr= [PPC]
|
||||||
|
@ -1233,6 +1241,10 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
|
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
|
||||||
memory.
|
memory.
|
||||||
|
|
||||||
|
memchunk=nn[KMG]
|
||||||
|
[KNL,SH] Allow user to override the default size for
|
||||||
|
per-device physically contiguous DMA buffers.
|
||||||
|
|
||||||
memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
|
memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
|
||||||
E820 memory map, as specified by the user.
|
E820 memory map, as specified by the user.
|
||||||
Such memmap=exactmap lines can be constructed based on
|
Such memmap=exactmap lines can be constructed based on
|
||||||
|
@ -1255,6 +1267,29 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
or
|
or
|
||||||
memmap=0x10000$0x18690000
|
memmap=0x10000$0x18690000
|
||||||
|
|
||||||
|
memory_corruption_check=0/1 [X86]
|
||||||
|
Some BIOSes seem to corrupt the first 64k of
|
||||||
|
memory when doing things like suspend/resume.
|
||||||
|
Setting this option will scan the memory
|
||||||
|
looking for corruption. Enabling this will
|
||||||
|
both detect corruption and prevent the kernel
|
||||||
|
from using the memory being corrupted.
|
||||||
|
However, its intended as a diagnostic tool; if
|
||||||
|
repeatable BIOS-originated corruption always
|
||||||
|
affects the same memory, you can use memmap=
|
||||||
|
to prevent the kernel from using that memory.
|
||||||
|
|
||||||
|
memory_corruption_check_size=size [X86]
|
||||||
|
By default it checks for corruption in the low
|
||||||
|
64k, making this memory unavailable for normal
|
||||||
|
use. Use this parameter to scan for
|
||||||
|
corruption in more or less memory.
|
||||||
|
|
||||||
|
memory_corruption_check_period=seconds [X86]
|
||||||
|
By default it checks for corruption every 60
|
||||||
|
seconds. Use this parameter to check at some
|
||||||
|
other rate. 0 disables periodic checking.
|
||||||
|
|
||||||
memtest= [KNL,X86] Enable memtest
|
memtest= [KNL,X86] Enable memtest
|
||||||
Format: <integer>
|
Format: <integer>
|
||||||
range: 0,4 : pattern number
|
range: 0,4 : pattern number
|
||||||
|
@ -1392,6 +1427,8 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
|
|
||||||
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
|
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
|
||||||
|
|
||||||
|
nodsp [SH] Disable hardware DSP at boot time.
|
||||||
|
|
||||||
noefi [X86-32,X86-64] Disable EFI runtime services support.
|
noefi [X86-32,X86-64] Disable EFI runtime services support.
|
||||||
|
|
||||||
noexec [IA-64]
|
noexec [IA-64]
|
||||||
|
@ -1408,13 +1445,15 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
noexec32=off: disable non-executable mappings
|
noexec32=off: disable non-executable mappings
|
||||||
read implies executable mappings
|
read implies executable mappings
|
||||||
|
|
||||||
|
nofpu [SH] Disable hardware FPU at boot time.
|
||||||
|
|
||||||
nofxsr [BUGS=X86-32] Disables x86 floating point extended
|
nofxsr [BUGS=X86-32] Disables x86 floating point extended
|
||||||
register save and restore. The kernel will only save
|
register save and restore. The kernel will only save
|
||||||
legacy floating-point registers on task switch.
|
legacy floating-point registers on task switch.
|
||||||
|
|
||||||
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
|
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
|
||||||
|
|
||||||
nohlt [BUGS=ARM]
|
nohlt [BUGS=ARM,SH]
|
||||||
|
|
||||||
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
|
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
|
||||||
instruction doesn't work correctly and not to
|
instruction doesn't work correctly and not to
|
||||||
|
@ -1452,6 +1491,12 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
|
|
||||||
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
|
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
|
||||||
|
|
||||||
|
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
|
||||||
|
|
||||||
|
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
|
||||||
|
default x2apic cluster mode on platforms
|
||||||
|
supporting x2apic.
|
||||||
|
|
||||||
noltlbs [PPC] Do not use large page/tlb entries for kernel
|
noltlbs [PPC] Do not use large page/tlb entries for kernel
|
||||||
lowmem mapping on PPC40x.
|
lowmem mapping on PPC40x.
|
||||||
|
|
||||||
|
@ -1571,7 +1616,7 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
See also Documentation/paride.txt.
|
See also Documentation/paride.txt.
|
||||||
|
|
||||||
pci=option[,option...] [PCI] various PCI subsystem options:
|
pci=option[,option...] [PCI] various PCI subsystem options:
|
||||||
off [X86-32] don't probe for the PCI bus
|
off [X86] don't probe for the PCI bus
|
||||||
bios [X86-32] force use of PCI BIOS, don't access
|
bios [X86-32] force use of PCI BIOS, don't access
|
||||||
the hardware directly. Use this if your machine
|
the hardware directly. Use this if your machine
|
||||||
has a non-standard PCI host bridge.
|
has a non-standard PCI host bridge.
|
||||||
|
@ -1579,9 +1624,9 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
hardware access methods are allowed. Use this
|
hardware access methods are allowed. Use this
|
||||||
if you experience crashes upon bootup and you
|
if you experience crashes upon bootup and you
|
||||||
suspect they are caused by the BIOS.
|
suspect they are caused by the BIOS.
|
||||||
conf1 [X86-32] Force use of PCI Configuration
|
conf1 [X86] Force use of PCI Configuration
|
||||||
Mechanism 1.
|
Mechanism 1.
|
||||||
conf2 [X86-32] Force use of PCI Configuration
|
conf2 [X86] Force use of PCI Configuration
|
||||||
Mechanism 2.
|
Mechanism 2.
|
||||||
noaer [PCIE] If the PCIEAER kernel config parameter is
|
noaer [PCIE] If the PCIEAER kernel config parameter is
|
||||||
enabled, this kernel boot option can be used to
|
enabled, this kernel boot option can be used to
|
||||||
|
@ -1601,37 +1646,37 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
this option if the kernel is unable to allocate
|
this option if the kernel is unable to allocate
|
||||||
IRQs or discover secondary PCI buses on your
|
IRQs or discover secondary PCI buses on your
|
||||||
motherboard.
|
motherboard.
|
||||||
rom [X86-32] Assign address space to expansion ROMs.
|
rom [X86] Assign address space to expansion ROMs.
|
||||||
Use with caution as certain devices share
|
Use with caution as certain devices share
|
||||||
address decoders between ROMs and other
|
address decoders between ROMs and other
|
||||||
resources.
|
resources.
|
||||||
norom [X86-32,X86_64] Do not assign address space to
|
norom [X86] Do not assign address space to
|
||||||
expansion ROMs that do not already have
|
expansion ROMs that do not already have
|
||||||
BIOS assigned address ranges.
|
BIOS assigned address ranges.
|
||||||
irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
|
irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
|
||||||
assigned automatically to PCI devices. You can
|
assigned automatically to PCI devices. You can
|
||||||
make the kernel exclude IRQs of your ISA cards
|
make the kernel exclude IRQs of your ISA cards
|
||||||
this way.
|
this way.
|
||||||
pirqaddr=0xAAAAA [X86-32] Specify the physical address
|
pirqaddr=0xAAAAA [X86] Specify the physical address
|
||||||
of the PIRQ table (normally generated
|
of the PIRQ table (normally generated
|
||||||
by the BIOS) if it is outside the
|
by the BIOS) if it is outside the
|
||||||
F0000h-100000h range.
|
F0000h-100000h range.
|
||||||
lastbus=N [X86-32] Scan all buses thru bus #N. Can be
|
lastbus=N [X86] Scan all buses thru bus #N. Can be
|
||||||
useful if the kernel is unable to find your
|
useful if the kernel is unable to find your
|
||||||
secondary buses and you want to tell it
|
secondary buses and you want to tell it
|
||||||
explicitly which ones they are.
|
explicitly which ones they are.
|
||||||
assign-busses [X86-32] Always assign all PCI bus
|
assign-busses [X86] Always assign all PCI bus
|
||||||
numbers ourselves, overriding
|
numbers ourselves, overriding
|
||||||
whatever the firmware may have done.
|
whatever the firmware may have done.
|
||||||
usepirqmask [X86-32] Honor the possible IRQ mask stored
|
usepirqmask [X86] Honor the possible IRQ mask stored
|
||||||
in the BIOS $PIR table. This is needed on
|
in the BIOS $PIR table. This is needed on
|
||||||
some systems with broken BIOSes, notably
|
some systems with broken BIOSes, notably
|
||||||
some HP Pavilion N5400 and Omnibook XE3
|
some HP Pavilion N5400 and Omnibook XE3
|
||||||
notebooks. This will have no effect if ACPI
|
notebooks. This will have no effect if ACPI
|
||||||
IRQ routing is enabled.
|
IRQ routing is enabled.
|
||||||
noacpi [X86-32] Do not use ACPI for IRQ routing
|
noacpi [X86] Do not use ACPI for IRQ routing
|
||||||
or for PCI scanning.
|
or for PCI scanning.
|
||||||
use_crs [X86-32] Use _CRS for PCI resource
|
use_crs [X86] Use _CRS for PCI resource
|
||||||
allocation.
|
allocation.
|
||||||
routeirq Do IRQ routing for all PCI devices.
|
routeirq Do IRQ routing for all PCI devices.
|
||||||
This is normally done in pci_enable_device(),
|
This is normally done in pci_enable_device(),
|
||||||
|
@ -1660,6 +1705,12 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
reserved for the CardBus bridge's memory
|
reserved for the CardBus bridge's memory
|
||||||
window. The default value is 64 megabytes.
|
window. The default value is 64 megabytes.
|
||||||
|
|
||||||
|
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
|
||||||
|
Management.
|
||||||
|
off Disable ASPM.
|
||||||
|
force Enable ASPM even on devices that claim not to support it.
|
||||||
|
WARNING: Forcing ASPM on may cause system lockups.
|
||||||
|
|
||||||
pcmv= [HW,PCMCIA] BadgePAD 4
|
pcmv= [HW,PCMCIA] BadgePAD 4
|
||||||
|
|
||||||
pd. [PARIDE]
|
pd. [PARIDE]
|
||||||
|
@ -1711,6 +1762,11 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
autoconfiguration.
|
autoconfiguration.
|
||||||
Ranges are in pairs (memory base and size).
|
Ranges are in pairs (memory base and size).
|
||||||
|
|
||||||
|
dynamic_printk
|
||||||
|
Enables pr_debug()/dev_dbg() calls if
|
||||||
|
CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. These can also
|
||||||
|
be switched on/off via <debugfs>/dynamic_printk/modules
|
||||||
|
|
||||||
print-fatal-signals=
|
print-fatal-signals=
|
||||||
[KNL] debug: print fatal signals
|
[KNL] debug: print fatal signals
|
||||||
print-fatal-signals=1: print segfault info to
|
print-fatal-signals=1: print segfault info to
|
||||||
|
@ -1913,6 +1969,12 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
shapers= [NET]
|
shapers= [NET]
|
||||||
Maximal number of shapers.
|
Maximal number of shapers.
|
||||||
|
|
||||||
|
show_msr= [x86] show boot-time MSR settings
|
||||||
|
Format: { <integer> }
|
||||||
|
Show boot-time (BIOS-initialized) MSR settings.
|
||||||
|
The parameter means the number of CPUs to show,
|
||||||
|
for example 1 means boot CPU only.
|
||||||
|
|
||||||
sim710= [SCSI,HW]
|
sim710= [SCSI,HW]
|
||||||
See header of drivers/scsi/sim710.c.
|
See header of drivers/scsi/sim710.c.
|
||||||
|
|
||||||
|
@ -2239,6 +2301,25 @@ and is between 256 and 4096 characters. It is defined in the file
|
||||||
autosuspended. Devices for which the delay is set
|
autosuspended. Devices for which the delay is set
|
||||||
to a negative value won't be autosuspended at all.
|
to a negative value won't be autosuspended at all.
|
||||||
|
|
||||||
|
usbcore.usbfs_snoop=
|
||||||
|
[USB] Set to log all usbfs traffic (default 0 = off).
|
||||||
|
|
||||||
|
usbcore.blinkenlights=
|
||||||
|
[USB] Set to cycle leds on hubs (default 0 = off).
|
||||||
|
|
||||||
|
usbcore.old_scheme_first=
|
||||||
|
[USB] Start with the old device initialization
|
||||||
|
scheme (default 0 = off).
|
||||||
|
|
||||||
|
usbcore.use_both_schemes=
|
||||||
|
[USB] Try the other device initialization scheme
|
||||||
|
if the first one fails (default 1 = enabled).
|
||||||
|
|
||||||
|
usbcore.initial_descriptor_timeout=
|
||||||
|
[USB] Specifies timeout for the initial 64-byte
|
||||||
|
USB_REQ_GET_DESCRIPTOR request in milliseconds
|
||||||
|
(default 5000 = 5.0 seconds).
|
||||||
|
|
||||||
usbhid.mousepoll=
|
usbhid.mousepoll=
|
||||||
[USBHID] The interval which mice are to be polled at.
|
[USBHID] The interval which mice are to be polled at.
|
||||||
|
|
||||||
|
|
|
@ -118,6 +118,10 @@ the name of the kobject, call kobject_rename():
|
||||||
|
|
||||||
int kobject_rename(struct kobject *kobj, const char *new_name);
|
int kobject_rename(struct kobject *kobj, const char *new_name);
|
||||||
|
|
||||||
|
Note kobject_rename does perform any locking or have a solid notion of
|
||||||
|
what names are valid so the provide must provide their own sanity checking
|
||||||
|
and serialization.
|
||||||
|
|
||||||
There is a function called kobject_set_name() but that is legacy cruft and
|
There is a function called kobject_set_name() but that is legacy cruft and
|
||||||
is being removed. If your code needs to call this function, it is
|
is being removed. If your code needs to call this function, it is
|
||||||
incorrect and needs to be fixed.
|
incorrect and needs to be fixed.
|
||||||
|
|
|
@ -0,0 +1,149 @@
|
||||||
|
Hard disk shock protection
|
||||||
|
==========================
|
||||||
|
|
||||||
|
Author: Elias Oltmanns <eo@nebensachen.de>
|
||||||
|
Last modified: 2008-10-03
|
||||||
|
|
||||||
|
|
||||||
|
0. Contents
|
||||||
|
-----------
|
||||||
|
|
||||||
|
1. Intro
|
||||||
|
2. The interface
|
||||||
|
3. References
|
||||||
|
4. CREDITS
|
||||||
|
|
||||||
|
|
||||||
|
1. Intro
|
||||||
|
--------
|
||||||
|
|
||||||
|
ATA/ATAPI-7 specifies the IDLE IMMEDIATE command with unload feature.
|
||||||
|
Issuing this command should cause the drive to switch to idle mode and
|
||||||
|
unload disk heads. This feature is being used in modern laptops in
|
||||||
|
conjunction with accelerometers and appropriate software to implement
|
||||||
|
a shock protection facility. The idea is to stop all I/O operations on
|
||||||
|
the internal hard drive and park its heads on the ramp when critical
|
||||||
|
situations are anticipated. The desire to have such a feature
|
||||||
|
available on GNU/Linux systems has been the original motivation to
|
||||||
|
implement a generic disk head parking interface in the Linux kernel.
|
||||||
|
Please note, however, that other components have to be set up on your
|
||||||
|
system in order to get disk shock protection working (see
|
||||||
|
section 3. References below for pointers to more information about
|
||||||
|
that).
|
||||||
|
|
||||||
|
|
||||||
|
2. The interface
|
||||||
|
----------------
|
||||||
|
|
||||||
|
For each ATA device, the kernel exports the file
|
||||||
|
block/*/device/unload_heads in sysfs (here assumed to be mounted under
|
||||||
|
/sys). Access to /sys/block/*/device/unload_heads is denied with
|
||||||
|
-EOPNOTSUPP if the device does not support the unload feature.
|
||||||
|
Otherwise, writing an integer value to this file will take the heads
|
||||||
|
of the respective drive off the platter and block all I/O operations
|
||||||
|
for the specified number of milliseconds. When the timeout expires and
|
||||||
|
no further disk head park request has been issued in the meantime,
|
||||||
|
normal operation will be resumed. The maximal value accepted for a
|
||||||
|
timeout is 30000 milliseconds. Exceeding this limit will return
|
||||||
|
-EOVERFLOW, but heads will be parked anyway and the timeout will be
|
||||||
|
set to 30 seconds. However, you can always change a timeout to any
|
||||||
|
value between 0 and 30000 by issuing a subsequent head park request
|
||||||
|
before the timeout of the previous one has expired. In particular, the
|
||||||
|
total timeout can exceed 30 seconds and, more importantly, you can
|
||||||
|
cancel a previously set timeout and resume normal operation
|
||||||
|
immediately by specifying a timeout of 0. Values below -2 are rejected
|
||||||
|
with -EINVAL (see below for the special meaning of -1 and -2). If the
|
||||||
|
timeout specified for a recent head park request has not yet expired,
|
||||||
|
reading from /sys/block/*/device/unload_heads will report the number
|
||||||
|
of milliseconds remaining until normal operation will be resumed;
|
||||||
|
otherwise, reading the unload_heads attribute will return 0.
|
||||||
|
|
||||||
|
For example, do the following in order to park the heads of drive
|
||||||
|
/dev/sda and stop all I/O operations for five seconds:
|
||||||
|
|
||||||
|
# echo 5000 > /sys/block/sda/device/unload_heads
|
||||||
|
|
||||||
|
A simple
|
||||||
|
|
||||||
|
# cat /sys/block/sda/device/unload_heads
|
||||||
|
|
||||||
|
will show you how many milliseconds are left before normal operation
|
||||||
|
will be resumed.
|
||||||
|
|
||||||
|
A word of caution: The fact that the interface operates on a basis of
|
||||||
|
milliseconds may raise expectations that cannot be satisfied in
|
||||||
|
reality. In fact, the ATA specs clearly state that the time for an
|
||||||
|
unload operation to complete is vendor specific. The hint in ATA-7
|
||||||
|
that this will typically be within 500 milliseconds apparently has
|
||||||
|
been dropped in ATA-8.
|
||||||
|
|
||||||
|
There is a technical detail of this implementation that may cause some
|
||||||
|
confusion and should be discussed here. When a head park request has
|
||||||
|
been issued to a device successfully, all I/O operations on the
|
||||||
|
controller port this device is attached to will be deferred. That is
|
||||||
|
to say, any other device that may be connected to the same port will
|
||||||
|
be affected too. The only exception is that a subsequent head unload
|
||||||
|
request to that other device will be executed immediately. Further
|
||||||
|
operations on that port will be deferred until the timeout specified
|
||||||
|
for either device on the port has expired. As far as PATA (old style
|
||||||
|
IDE) configurations are concerned, there can only be two devices
|
||||||
|
attached to any single port. In SATA world we have port multipliers
|
||||||
|
which means that a user-issued head parking request to one device may
|
||||||
|
actually result in stopping I/O to a whole bunch of devices. However,
|
||||||
|
since this feature is supposed to be used on laptops and does not seem
|
||||||
|
to be very useful in any other environment, there will be mostly one
|
||||||
|
device per port. Even if the CD/DVD writer happens to be connected to
|
||||||
|
the same port as the hard drive, it generally *should* recover just
|
||||||
|
fine from the occasional buffer under-run incurred by a head park
|
||||||
|
request to the HD. Actually, when you are using an ide driver rather
|
||||||
|
than its libata counterpart (i.e. your disk is called /dev/hda
|
||||||
|
instead of /dev/sda), then parking the heads of one drive (drive X)
|
||||||
|
will generally not affect the mode of operation of another drive
|
||||||
|
(drive Y) on the same port as described above. It is only when a port
|
||||||
|
reset is required to recover from an exception on drive Y that further
|
||||||
|
I/O operations on that drive (and the reset itself) will be delayed
|
||||||
|
until drive X is no longer in the parked state.
|
||||||
|
|
||||||
|
Finally, there are some hard drives that only comply with an earlier
|
||||||
|
version of the ATA standard than ATA-7, but do support the unload
|
||||||
|
feature nonetheless. Unfortunately, there is no safe way Linux can
|
||||||
|
detect these devices, so you won't be able to write to the
|
||||||
|
unload_heads attribute. If you know that your device really does
|
||||||
|
support the unload feature (for instance, because the vendor of your
|
||||||
|
laptop or the hard drive itself told you so), then you can tell the
|
||||||
|
kernel to enable the usage of this feature for that drive by writing
|
||||||
|
the special value -1 to the unload_heads attribute:
|
||||||
|
|
||||||
|
# echo -1 > /sys/block/sda/device/unload_heads
|
||||||
|
|
||||||
|
will enable the feature for /dev/sda, and giving -2 instead of -1 will
|
||||||
|
disable it again.
|
||||||
|
|
||||||
|
|
||||||
|
3. References
|
||||||
|
-------------
|
||||||
|
|
||||||
|
There are several laptops from different vendors featuring shock
|
||||||
|
protection capabilities. As manufacturers have refused to support open
|
||||||
|
source development of the required software components so far, Linux
|
||||||
|
support for shock protection varies considerably between different
|
||||||
|
hardware implementations. Ideally, this section should contain a list
|
||||||
|
of pointers at different projects aiming at an implementation of shock
|
||||||
|
protection on different systems. Unfortunately, I only know of a
|
||||||
|
single project which, although still considered experimental, is fit
|
||||||
|
for use. Please feel free to add projects that have been the victims
|
||||||
|
of my ignorance.
|
||||||
|
|
||||||
|
- http://www.thinkwiki.org/wiki/HDAPS
|
||||||
|
See this page for information about Linux support of the hard disk
|
||||||
|
active protection system as implemented in IBM/Lenovo Thinkpads.
|
||||||
|
|
||||||
|
|
||||||
|
4. CREDITS
|
||||||
|
----------
|
||||||
|
|
||||||
|
This implementation of disk head parking has been inspired by a patch
|
||||||
|
originally published by Jon Escombe <lists@dresco.co.uk>. My efforts
|
||||||
|
to develop an implementation of this feature that is fit to be merged
|
||||||
|
into mainline have been aided by various kernel developers, in
|
||||||
|
particular by Tejun Heo and Bartlomiej Zolnierkiewicz.
|
|
@ -50,10 +50,12 @@ Connecting a function (probe) to a marker is done by providing a probe (function
|
||||||
to call) for the specific marker through marker_probe_register() and can be
|
to call) for the specific marker through marker_probe_register() and can be
|
||||||
activated by calling marker_arm(). Marker deactivation can be done by calling
|
activated by calling marker_arm(). Marker deactivation can be done by calling
|
||||||
marker_disarm() as many times as marker_arm() has been called. Removing a probe
|
marker_disarm() as many times as marker_arm() has been called. Removing a probe
|
||||||
is done through marker_probe_unregister(); it will disarm the probe and make
|
is done through marker_probe_unregister(); it will disarm the probe.
|
||||||
sure there is no caller left using the probe when it returns. Probe removal is
|
marker_synchronize_unregister() must be called before the end of the module exit
|
||||||
preempt-safe because preemption is disabled around the probe call. See the
|
function to make sure there is no caller left using the probe. This, and the
|
||||||
"Probe example" section below for a sample probe module.
|
fact that preemption is disabled around the probe call, make sure that probe
|
||||||
|
removal and module unload are safe. See the "Probe example" section below for a
|
||||||
|
sample probe module.
|
||||||
|
|
||||||
The marker mechanism supports inserting multiple instances of the same marker.
|
The marker mechanism supports inserting multiple instances of the same marker.
|
||||||
Markers can be put in inline functions, inlined static functions, and
|
Markers can be put in inline functions, inlined static functions, and
|
||||||
|
|
|
@ -0,0 +1,714 @@
|
||||||
|
Introduction
|
||||||
|
============
|
||||||
|
|
||||||
|
Having looked at the linux mtd/nand driver and more specific at nand_ecc.c
|
||||||
|
I felt there was room for optimisation. I bashed the code for a few hours
|
||||||
|
performing tricks like table lookup removing superfluous code etc.
|
||||||
|
After that the speed was increased by 35-40%.
|
||||||
|
Still I was not too happy as I felt there was additional room for improvement.
|
||||||
|
|
||||||
|
Bad! I was hooked.
|
||||||
|
I decided to annotate my steps in this file. Perhaps it is useful to someone
|
||||||
|
or someone learns something from it.
|
||||||
|
|
||||||
|
|
||||||
|
The problem
|
||||||
|
===========
|
||||||
|
|
||||||
|
NAND flash (at least SLC one) typically has sectors of 256 bytes.
|
||||||
|
However NAND flash is not extremely reliable so some error detection
|
||||||
|
(and sometimes correction) is needed.
|
||||||
|
|
||||||
|
This is done by means of a Hamming code. I'll try to explain it in
|
||||||
|
laymans terms (and apologies to all the pro's in the field in case I do
|
||||||
|
not use the right terminology, my coding theory class was almost 30
|
||||||
|
years ago, and I must admit it was not one of my favourites).
|
||||||
|
|
||||||
|
As I said before the ecc calculation is performed on sectors of 256
|
||||||
|
bytes. This is done by calculating several parity bits over the rows and
|
||||||
|
columns. The parity used is even parity which means that the parity bit = 1
|
||||||
|
if the data over which the parity is calculated is 1 and the parity bit = 0
|
||||||
|
if the data over which the parity is calculated is 0. So the total
|
||||||
|
number of bits over the data over which the parity is calculated + the
|
||||||
|
parity bit is even. (see wikipedia if you can't follow this).
|
||||||
|
Parity is often calculated by means of an exclusive or operation,
|
||||||
|
sometimes also referred to as xor. In C the operator for xor is ^
|
||||||
|
|
||||||
|
Back to ecc.
|
||||||
|
Let's give a small figure:
|
||||||
|
|
||||||
|
byte 0: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp0 rp2 rp4 ... rp14
|
||||||
|
byte 1: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp1 rp2 rp4 ... rp14
|
||||||
|
byte 2: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp0 rp3 rp4 ... rp14
|
||||||
|
byte 3: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp1 rp3 rp4 ... rp14
|
||||||
|
byte 4: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp0 rp2 rp5 ... rp14
|
||||||
|
....
|
||||||
|
byte 254: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp0 rp3 rp5 ... rp15
|
||||||
|
byte 255: bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 rp1 rp3 rp5 ... rp15
|
||||||
|
cp1 cp0 cp1 cp0 cp1 cp0 cp1 cp0
|
||||||
|
cp3 cp3 cp2 cp2 cp3 cp3 cp2 cp2
|
||||||
|
cp5 cp5 cp5 cp5 cp4 cp4 cp4 cp4
|
||||||
|
|
||||||
|
This figure represents a sector of 256 bytes.
|
||||||
|
cp is my abbreviaton for column parity, rp for row parity.
|
||||||
|
|
||||||
|
Let's start to explain column parity.
|
||||||
|
cp0 is the parity that belongs to all bit0, bit2, bit4, bit6.
|
||||||
|
so the sum of all bit0, bit2, bit4 and bit6 values + cp0 itself is even.
|
||||||
|
Similarly cp1 is the sum of all bit1, bit3, bit5 and bit7.
|
||||||
|
cp2 is the parity over bit0, bit1, bit4 and bit5
|
||||||
|
cp3 is the parity over bit2, bit3, bit6 and bit7.
|
||||||
|
cp4 is the parity over bit0, bit1, bit2 and bit3.
|
||||||
|
cp5 is the parity over bit4, bit5, bit6 and bit7.
|
||||||
|
Note that each of cp0 .. cp5 is exactly one bit.
|
||||||
|
|
||||||
|
Row parity actually works almost the same.
|
||||||
|
rp0 is the parity of all even bytes (0, 2, 4, 6, ... 252, 254)
|
||||||
|
rp1 is the parity of all odd bytes (1, 3, 5, 7, ..., 253, 255)
|
||||||
|
rp2 is the parity of all bytes 0, 1, 4, 5, 8, 9, ...
|
||||||
|
(so handle two bytes, then skip 2 bytes).
|
||||||
|
rp3 is covers the half rp2 does not cover (bytes 2, 3, 6, 7, 10, 11, ...)
|
||||||
|
for rp4 the rule is cover 4 bytes, skip 4 bytes, cover 4 bytes, skip 4 etc.
|
||||||
|
so rp4 calculates parity over bytes 0, 1, 2, 3, 8, 9, 10, 11, 16, ...)
|
||||||
|
and rp5 covers the other half, so bytes 4, 5, 6, 7, 12, 13, 14, 15, 20, ..
|
||||||
|
The story now becomes quite boring. I guess you get the idea.
|
||||||
|
rp6 covers 8 bytes then skips 8 etc
|
||||||
|
rp7 skips 8 bytes then covers 8 etc
|
||||||
|
rp8 covers 16 bytes then skips 16 etc
|
||||||
|
rp9 skips 16 bytes then covers 16 etc
|
||||||
|
rp10 covers 32 bytes then skips 32 etc
|
||||||
|
rp11 skips 32 bytes then covers 32 etc
|
||||||
|
rp12 covers 64 bytes then skips 64 etc
|
||||||
|
rp13 skips 64 bytes then covers 64 etc
|
||||||
|
rp14 covers 128 bytes then skips 128
|
||||||
|
rp15 skips 128 bytes then covers 128
|
||||||
|
|
||||||
|
In the end the parity bits are grouped together in three bytes as
|
||||||
|
follows:
|
||||||
|
ECC Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
|
||||||
|
ECC 0 rp07 rp06 rp05 rp04 rp03 rp02 rp01 rp00
|
||||||
|
ECC 1 rp15 rp14 rp13 rp12 rp11 rp10 rp09 rp08
|
||||||
|
ECC 2 cp5 cp4 cp3 cp2 cp1 cp0 1 1
|
||||||
|
|
||||||
|
I detected after writing this that ST application note AN1823
|
||||||
|
(http://www.st.com/stonline/books/pdf/docs/10123.pdf) gives a much
|
||||||
|
nicer picture.(but they use line parity as term where I use row parity)
|
||||||
|
Oh well, I'm graphically challenged, so suffer with me for a moment :-)
|
||||||
|
And I could not reuse the ST picture anyway for copyright reasons.
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 0
|
||||||
|
=========
|
||||||
|
|
||||||
|
Implementing the parity calculation is pretty simple.
|
||||||
|
In C pseudocode:
|
||||||
|
for (i = 0; i < 256; i++)
|
||||||
|
{
|
||||||
|
if (i & 0x01)
|
||||||
|
rp1 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp1;
|
||||||
|
else
|
||||||
|
rp0 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp1;
|
||||||
|
if (i & 0x02)
|
||||||
|
rp3 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp3;
|
||||||
|
else
|
||||||
|
rp2 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp2;
|
||||||
|
if (i & 0x04)
|
||||||
|
rp5 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp5;
|
||||||
|
else
|
||||||
|
rp4 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp4;
|
||||||
|
if (i & 0x08)
|
||||||
|
rp7 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp7;
|
||||||
|
else
|
||||||
|
rp6 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp6;
|
||||||
|
if (i & 0x10)
|
||||||
|
rp9 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp9;
|
||||||
|
else
|
||||||
|
rp8 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp8;
|
||||||
|
if (i & 0x20)
|
||||||
|
rp11 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp11;
|
||||||
|
else
|
||||||
|
rp10 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp10;
|
||||||
|
if (i & 0x40)
|
||||||
|
rp13 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp13;
|
||||||
|
else
|
||||||
|
rp12 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp12;
|
||||||
|
if (i & 0x80)
|
||||||
|
rp15 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp15;
|
||||||
|
else
|
||||||
|
rp14 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp14;
|
||||||
|
cp0 = bit6 ^ bit4 ^ bit2 ^ bit0 ^ cp0;
|
||||||
|
cp1 = bit7 ^ bit5 ^ bit3 ^ bit1 ^ cp1;
|
||||||
|
cp2 = bit5 ^ bit4 ^ bit1 ^ bit0 ^ cp2;
|
||||||
|
cp3 = bit7 ^ bit6 ^ bit3 ^ bit2 ^ cp3
|
||||||
|
cp4 = bit3 ^ bit2 ^ bit1 ^ bit0 ^ cp4
|
||||||
|
cp5 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ cp5
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 0
|
||||||
|
==========
|
||||||
|
|
||||||
|
C does have bitwise operators but not really operators to do the above
|
||||||
|
efficiently (and most hardware has no such instructions either).
|
||||||
|
Therefore without implementing this it was clear that the code above was
|
||||||
|
not going to bring me a Nobel prize :-)
|
||||||
|
|
||||||
|
Fortunately the exclusive or operation is commutative, so we can combine
|
||||||
|
the values in any order. So instead of calculating all the bits
|
||||||
|
individually, let us try to rearrange things.
|
||||||
|
For the column parity this is easy. We can just xor the bytes and in the
|
||||||
|
end filter out the relevant bits. This is pretty nice as it will bring
|
||||||
|
all cp calculation out of the if loop.
|
||||||
|
|
||||||
|
Similarly we can first xor the bytes for the various rows.
|
||||||
|
This leads to:
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 1
|
||||||
|
=========
|
||||||
|
|
||||||
|
const char parity[256] = {
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
|
||||||
|
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0
|
||||||
|
};
|
||||||
|
|
||||||
|
void ecc1(const unsigned char *buf, unsigned char *code)
|
||||||
|
{
|
||||||
|
int i;
|
||||||
|
const unsigned char *bp = buf;
|
||||||
|
unsigned char cur;
|
||||||
|
unsigned char rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7;
|
||||||
|
unsigned char rp8, rp9, rp10, rp11, rp12, rp13, rp14, rp15;
|
||||||
|
unsigned char par;
|
||||||
|
|
||||||
|
par = 0;
|
||||||
|
rp0 = 0; rp1 = 0; rp2 = 0; rp3 = 0;
|
||||||
|
rp4 = 0; rp5 = 0; rp6 = 0; rp7 = 0;
|
||||||
|
rp8 = 0; rp9 = 0; rp10 = 0; rp11 = 0;
|
||||||
|
rp12 = 0; rp13 = 0; rp14 = 0; rp15 = 0;
|
||||||
|
|
||||||
|
for (i = 0; i < 256; i++)
|
||||||
|
{
|
||||||
|
cur = *bp++;
|
||||||
|
par ^= cur;
|
||||||
|
if (i & 0x01) rp1 ^= cur; else rp0 ^= cur;
|
||||||
|
if (i & 0x02) rp3 ^= cur; else rp2 ^= cur;
|
||||||
|
if (i & 0x04) rp5 ^= cur; else rp4 ^= cur;
|
||||||
|
if (i & 0x08) rp7 ^= cur; else rp6 ^= cur;
|
||||||
|
if (i & 0x10) rp9 ^= cur; else rp8 ^= cur;
|
||||||
|
if (i & 0x20) rp11 ^= cur; else rp10 ^= cur;
|
||||||
|
if (i & 0x40) rp13 ^= cur; else rp12 ^= cur;
|
||||||
|
if (i & 0x80) rp15 ^= cur; else rp14 ^= cur;
|
||||||
|
}
|
||||||
|
code[0] =
|
||||||
|
(parity[rp7] << 7) |
|
||||||
|
(parity[rp6] << 6) |
|
||||||
|
(parity[rp5] << 5) |
|
||||||
|
(parity[rp4] << 4) |
|
||||||
|
(parity[rp3] << 3) |
|
||||||
|
(parity[rp2] << 2) |
|
||||||
|
(parity[rp1] << 1) |
|
||||||
|
(parity[rp0]);
|
||||||
|
code[1] =
|
||||||
|
(parity[rp15] << 7) |
|
||||||
|
(parity[rp14] << 6) |
|
||||||
|
(parity[rp13] << 5) |
|
||||||
|
(parity[rp12] << 4) |
|
||||||
|
(parity[rp11] << 3) |
|
||||||
|
(parity[rp10] << 2) |
|
||||||
|
(parity[rp9] << 1) |
|
||||||
|
(parity[rp8]);
|
||||||
|
code[2] =
|
||||||
|
(parity[par & 0xf0] << 7) |
|
||||||
|
(parity[par & 0x0f] << 6) |
|
||||||
|
(parity[par & 0xcc] << 5) |
|
||||||
|
(parity[par & 0x33] << 4) |
|
||||||
|
(parity[par & 0xaa] << 3) |
|
||||||
|
(parity[par & 0x55] << 2);
|
||||||
|
code[0] = ~code[0];
|
||||||
|
code[1] = ~code[1];
|
||||||
|
code[2] = ~code[2];
|
||||||
|
}
|
||||||
|
|
||||||
|
Still pretty straightforward. The last three invert statements are there to
|
||||||
|
give a checksum of 0xff 0xff 0xff for an empty flash. In an empty flash
|
||||||
|
all data is 0xff, so the checksum then matches.
|
||||||
|
|
||||||
|
I also introduced the parity lookup. I expected this to be the fastest
|
||||||
|
way to calculate the parity, but I will investigate alternatives later
|
||||||
|
on.
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 1
|
||||||
|
==========
|
||||||
|
|
||||||
|
The code works, but is not terribly efficient. On my system it took
|
||||||
|
almost 4 times as much time as the linux driver code. But hey, if it was
|
||||||
|
*that* easy this would have been done long before.
|
||||||
|
No pain. no gain.
|
||||||
|
|
||||||
|
Fortunately there is plenty of room for improvement.
|
||||||
|
|
||||||
|
In step 1 we moved from bit-wise calculation to byte-wise calculation.
|
||||||
|
However in C we can also use the unsigned long data type and virtually
|
||||||
|
every modern microprocessor supports 32 bit operations, so why not try
|
||||||
|
to write our code in such a way that we process data in 32 bit chunks.
|
||||||
|
|
||||||
|
Of course this means some modification as the row parity is byte by
|
||||||
|
byte. A quick analysis:
|
||||||
|
for the column parity we use the par variable. When extending to 32 bits
|
||||||
|
we can in the end easily calculate p0 and p1 from it.
|
||||||
|
(because par now consists of 4 bytes, contributing to rp1, rp0, rp1, rp0
|
||||||
|
respectively)
|
||||||
|
also rp2 and rp3 can be easily retrieved from par as rp3 covers the
|
||||||
|
first two bytes and rp2 the last two bytes.
|
||||||
|
|
||||||
|
Note that of course now the loop is executed only 64 times (256/4).
|
||||||
|
And note that care must taken wrt byte ordering. The way bytes are
|
||||||
|
ordered in a long is machine dependent, and might affect us.
|
||||||
|
Anyway, if there is an issue: this code is developed on x86 (to be
|
||||||
|
precise: a DELL PC with a D920 Intel CPU)
|
||||||
|
|
||||||
|
And of course the performance might depend on alignment, but I expect
|
||||||
|
that the I/O buffers in the nand driver are aligned properly (and
|
||||||
|
otherwise that should be fixed to get maximum performance).
|
||||||
|
|
||||||
|
Let's give it a try...
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 2
|
||||||
|
=========
|
||||||
|
|
||||||
|
extern const char parity[256];
|
||||||
|
|
||||||
|
void ecc2(const unsigned char *buf, unsigned char *code)
|
||||||
|
{
|
||||||
|
int i;
|
||||||
|
const unsigned long *bp = (unsigned long *)buf;
|
||||||
|
unsigned long cur;
|
||||||
|
unsigned long rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7;
|
||||||
|
unsigned long rp8, rp9, rp10, rp11, rp12, rp13, rp14, rp15;
|
||||||
|
unsigned long par;
|
||||||
|
|
||||||
|
par = 0;
|
||||||
|
rp0 = 0; rp1 = 0; rp2 = 0; rp3 = 0;
|
||||||
|
rp4 = 0; rp5 = 0; rp6 = 0; rp7 = 0;
|
||||||
|
rp8 = 0; rp9 = 0; rp10 = 0; rp11 = 0;
|
||||||
|
rp12 = 0; rp13 = 0; rp14 = 0; rp15 = 0;
|
||||||
|
|
||||||
|
for (i = 0; i < 64; i++)
|
||||||
|
{
|
||||||
|
cur = *bp++;
|
||||||
|
par ^= cur;
|
||||||
|
if (i & 0x01) rp5 ^= cur; else rp4 ^= cur;
|
||||||
|
if (i & 0x02) rp7 ^= cur; else rp6 ^= cur;
|
||||||
|
if (i & 0x04) rp9 ^= cur; else rp8 ^= cur;
|
||||||
|
if (i & 0x08) rp11 ^= cur; else rp10 ^= cur;
|
||||||
|
if (i & 0x10) rp13 ^= cur; else rp12 ^= cur;
|
||||||
|
if (i & 0x20) rp15 ^= cur; else rp14 ^= cur;
|
||||||
|
}
|
||||||
|
/*
|
||||||
|
we need to adapt the code generation for the fact that rp vars are now
|
||||||
|
long; also the column parity calculation needs to be changed.
|
||||||
|
we'll bring rp4 to 15 back to single byte entities by shifting and
|
||||||
|
xoring
|
||||||
|
*/
|
||||||
|
rp4 ^= (rp4 >> 16); rp4 ^= (rp4 >> 8); rp4 &= 0xff;
|
||||||
|
rp5 ^= (rp5 >> 16); rp5 ^= (rp5 >> 8); rp5 &= 0xff;
|
||||||
|
rp6 ^= (rp6 >> 16); rp6 ^= (rp6 >> 8); rp6 &= 0xff;
|
||||||
|
rp7 ^= (rp7 >> 16); rp7 ^= (rp7 >> 8); rp7 &= 0xff;
|
||||||
|
rp8 ^= (rp8 >> 16); rp8 ^= (rp8 >> 8); rp8 &= 0xff;
|
||||||
|
rp9 ^= (rp9 >> 16); rp9 ^= (rp9 >> 8); rp9 &= 0xff;
|
||||||
|
rp10 ^= (rp10 >> 16); rp10 ^= (rp10 >> 8); rp10 &= 0xff;
|
||||||
|
rp11 ^= (rp11 >> 16); rp11 ^= (rp11 >> 8); rp11 &= 0xff;
|
||||||
|
rp12 ^= (rp12 >> 16); rp12 ^= (rp12 >> 8); rp12 &= 0xff;
|
||||||
|
rp13 ^= (rp13 >> 16); rp13 ^= (rp13 >> 8); rp13 &= 0xff;
|
||||||
|
rp14 ^= (rp14 >> 16); rp14 ^= (rp14 >> 8); rp14 &= 0xff;
|
||||||
|
rp15 ^= (rp15 >> 16); rp15 ^= (rp15 >> 8); rp15 &= 0xff;
|
||||||
|
rp3 = (par >> 16); rp3 ^= (rp3 >> 8); rp3 &= 0xff;
|
||||||
|
rp2 = par & 0xffff; rp2 ^= (rp2 >> 8); rp2 &= 0xff;
|
||||||
|
par ^= (par >> 16);
|
||||||
|
rp1 = (par >> 8); rp1 &= 0xff;
|
||||||
|
rp0 = (par & 0xff);
|
||||||
|
par ^= (par >> 8); par &= 0xff;
|
||||||
|
|
||||||
|
code[0] =
|
||||||
|
(parity[rp7] << 7) |
|
||||||
|
(parity[rp6] << 6) |
|
||||||
|
(parity[rp5] << 5) |
|
||||||
|
(parity[rp4] << 4) |
|
||||||
|
(parity[rp3] << 3) |
|
||||||
|
(parity[rp2] << 2) |
|
||||||
|
(parity[rp1] << 1) |
|
||||||
|
(parity[rp0]);
|
||||||
|
code[1] =
|
||||||
|
(parity[rp15] << 7) |
|
||||||
|
(parity[rp14] << 6) |
|
||||||
|
(parity[rp13] << 5) |
|
||||||
|
(parity[rp12] << 4) |
|
||||||
|
(parity[rp11] << 3) |
|
||||||
|
(parity[rp10] << 2) |
|
||||||
|
(parity[rp9] << 1) |
|
||||||
|
(parity[rp8]);
|
||||||
|
code[2] =
|
||||||
|
(parity[par & 0xf0] << 7) |
|
||||||
|
(parity[par & 0x0f] << 6) |
|
||||||
|
(parity[par & 0xcc] << 5) |
|
||||||
|
(parity[par & 0x33] << 4) |
|
||||||
|
(parity[par & 0xaa] << 3) |
|
||||||
|
(parity[par & 0x55] << 2);
|
||||||
|
code[0] = ~code[0];
|
||||||
|
code[1] = ~code[1];
|
||||||
|
code[2] = ~code[2];
|
||||||
|
}
|
||||||
|
|
||||||
|
The parity array is not shown any more. Note also that for these
|
||||||
|
examples I kinda deviated from my regular programming style by allowing
|
||||||
|
multiple statements on a line, not using { } in then and else blocks
|
||||||
|
with only a single statement and by using operators like ^=
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 2
|
||||||
|
==========
|
||||||
|
|
||||||
|
The code (of course) works, and hurray: we are a little bit faster than
|
||||||
|
the linux driver code (about 15%). But wait, don't cheer too quickly.
|
||||||
|
THere is more to be gained.
|
||||||
|
If we look at e.g. rp14 and rp15 we see that we either xor our data with
|
||||||
|
rp14 or with rp15. However we also have par which goes over all data.
|
||||||
|
This means there is no need to calculate rp14 as it can be calculated from
|
||||||
|
rp15 through rp14 = par ^ rp15;
|
||||||
|
(or if desired we can avoid calculating rp15 and calculate it from
|
||||||
|
rp14). That is why some places refer to inverse parity.
|
||||||
|
Of course the same thing holds for rp4/5, rp6/7, rp8/9, rp10/11 and rp12/13.
|
||||||
|
Effectively this means we can eliminate the else clause from the if
|
||||||
|
statements. Also we can optimise the calculation in the end a little bit
|
||||||
|
by going from long to byte first. Actually we can even avoid the table
|
||||||
|
lookups
|
||||||
|
|
||||||
|
Attempt 3
|
||||||
|
=========
|
||||||
|
|
||||||
|
Odd replaced:
|
||||||
|
if (i & 0x01) rp5 ^= cur; else rp4 ^= cur;
|
||||||
|
if (i & 0x02) rp7 ^= cur; else rp6 ^= cur;
|
||||||
|
if (i & 0x04) rp9 ^= cur; else rp8 ^= cur;
|
||||||
|
if (i & 0x08) rp11 ^= cur; else rp10 ^= cur;
|
||||||
|
if (i & 0x10) rp13 ^= cur; else rp12 ^= cur;
|
||||||
|
if (i & 0x20) rp15 ^= cur; else rp14 ^= cur;
|
||||||
|
with
|
||||||
|
if (i & 0x01) rp5 ^= cur;
|
||||||
|
if (i & 0x02) rp7 ^= cur;
|
||||||
|
if (i & 0x04) rp9 ^= cur;
|
||||||
|
if (i & 0x08) rp11 ^= cur;
|
||||||
|
if (i & 0x10) rp13 ^= cur;
|
||||||
|
if (i & 0x20) rp15 ^= cur;
|
||||||
|
|
||||||
|
and outside the loop added:
|
||||||
|
rp4 = par ^ rp5;
|
||||||
|
rp6 = par ^ rp7;
|
||||||
|
rp8 = par ^ rp9;
|
||||||
|
rp10 = par ^ rp11;
|
||||||
|
rp12 = par ^ rp13;
|
||||||
|
rp14 = par ^ rp15;
|
||||||
|
|
||||||
|
And after that the code takes about 30% more time, although the number of
|
||||||
|
statements is reduced. This is also reflected in the assembly code.
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 3
|
||||||
|
==========
|
||||||
|
|
||||||
|
Very weird. Guess it has to do with caching or instruction parallellism
|
||||||
|
or so. I also tried on an eeePC (Celeron, clocked at 900 Mhz). Interesting
|
||||||
|
observation was that this one is only 30% slower (according to time)
|
||||||
|
executing the code as my 3Ghz D920 processor.
|
||||||
|
|
||||||
|
Well, it was expected not to be easy so maybe instead move to a
|
||||||
|
different track: let's move back to the code from attempt2 and do some
|
||||||
|
loop unrolling. This will eliminate a few if statements. I'll try
|
||||||
|
different amounts of unrolling to see what works best.
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 4
|
||||||
|
=========
|
||||||
|
|
||||||
|
Unrolled the loop 1, 2, 3 and 4 times.
|
||||||
|
For 4 the code starts with:
|
||||||
|
|
||||||
|
for (i = 0; i < 4; i++)
|
||||||
|
{
|
||||||
|
cur = *bp++;
|
||||||
|
par ^= cur;
|
||||||
|
rp4 ^= cur;
|
||||||
|
rp6 ^= cur;
|
||||||
|
rp8 ^= cur;
|
||||||
|
rp10 ^= cur;
|
||||||
|
if (i & 0x1) rp13 ^= cur; else rp12 ^= cur;
|
||||||
|
if (i & 0x2) rp15 ^= cur; else rp14 ^= cur;
|
||||||
|
cur = *bp++;
|
||||||
|
par ^= cur;
|
||||||
|
rp5 ^= cur;
|
||||||
|
rp6 ^= cur;
|
||||||
|
...
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 4
|
||||||
|
==========
|
||||||
|
|
||||||
|
Unrolling once gains about 15%
|
||||||
|
Unrolling twice keeps the gain at about 15%
|
||||||
|
Unrolling three times gives a gain of 30% compared to attempt 2.
|
||||||
|
Unrolling four times gives a marginal improvement compared to unrolling
|
||||||
|
three times.
|
||||||
|
|
||||||
|
I decided to proceed with a four time unrolled loop anyway. It was my gut
|
||||||
|
feeling that in the next steps I would obtain additional gain from it.
|
||||||
|
|
||||||
|
The next step was triggered by the fact that par contains the xor of all
|
||||||
|
bytes and rp4 and rp5 each contain the xor of half of the bytes.
|
||||||
|
So in effect par = rp4 ^ rp5. But as xor is commutative we can also say
|
||||||
|
that rp5 = par ^ rp4. So no need to keep both rp4 and rp5 around. We can
|
||||||
|
eliminate rp5 (or rp4, but I already foresaw another optimisation).
|
||||||
|
The same holds for rp6/7, rp8/9, rp10/11 rp12/13 and rp14/15.
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 5
|
||||||
|
=========
|
||||||
|
|
||||||
|
Effectively so all odd digit rp assignments in the loop were removed.
|
||||||
|
This included the else clause of the if statements.
|
||||||
|
Of course after the loop we need to correct things by adding code like:
|
||||||
|
rp5 = par ^ rp4;
|
||||||
|
Also the initial assignments (rp5 = 0; etc) could be removed.
|
||||||
|
Along the line I also removed the initialisation of rp0/1/2/3.
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 5
|
||||||
|
==========
|
||||||
|
|
||||||
|
Measurements showed this was a good move. The run-time roughly halved
|
||||||
|
compared with attempt 4 with 4 times unrolled, and we only require 1/3rd
|
||||||
|
of the processor time compared to the current code in the linux kernel.
|
||||||
|
|
||||||
|
However, still I thought there was more. I didn't like all the if
|
||||||
|
statements. Why not keep a running parity and only keep the last if
|
||||||
|
statement. Time for yet another version!
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 6
|
||||||
|
=========
|
||||||
|
|
||||||
|
THe code within the for loop was changed to:
|
||||||
|
|
||||||
|
for (i = 0; i < 4; i++)
|
||||||
|
{
|
||||||
|
cur = *bp++; tmppar = cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= tmppar;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp8 ^= tmppar;
|
||||||
|
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
|
||||||
|
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur; rp8 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur; rp8 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp8 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp8 ^= cur;
|
||||||
|
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur;
|
||||||
|
|
||||||
|
par ^= tmppar;
|
||||||
|
if ((i & 0x1) == 0) rp12 ^= tmppar;
|
||||||
|
if ((i & 0x2) == 0) rp14 ^= tmppar;
|
||||||
|
}
|
||||||
|
|
||||||
|
As you can see tmppar is used to accumulate the parity within a for
|
||||||
|
iteration. In the last 3 statements is is added to par and, if needed,
|
||||||
|
to rp12 and rp14.
|
||||||
|
|
||||||
|
While making the changes I also found that I could exploit that tmppar
|
||||||
|
contains the running parity for this iteration. So instead of having:
|
||||||
|
rp4 ^= cur; rp6 = cur;
|
||||||
|
I removed the rp6 = cur; statement and did rp6 ^= tmppar; on next
|
||||||
|
statement. A similar change was done for rp8 and rp10
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 6
|
||||||
|
==========
|
||||||
|
|
||||||
|
Measuring this code again showed big gain. When executing the original
|
||||||
|
linux code 1 million times, this took about 1 second on my system.
|
||||||
|
(using time to measure the performance). After this iteration I was back
|
||||||
|
to 0.075 sec. Actually I had to decide to start measuring over 10
|
||||||
|
million interations in order not to loose too much accuracy. This one
|
||||||
|
definitely seemed to be the jackpot!
|
||||||
|
|
||||||
|
There is a little bit more room for improvement though. There are three
|
||||||
|
places with statements:
|
||||||
|
rp4 ^= cur; rp6 ^= cur;
|
||||||
|
It seems more efficient to also maintain a variable rp4_6 in the while
|
||||||
|
loop; This eliminates 3 statements per loop. Of course after the loop we
|
||||||
|
need to correct by adding:
|
||||||
|
rp4 ^= rp4_6;
|
||||||
|
rp6 ^= rp4_6
|
||||||
|
Furthermore there are 4 sequential assingments to rp8. This can be
|
||||||
|
encoded slightly more efficient by saving tmppar before those 4 lines
|
||||||
|
and later do rp8 = rp8 ^ tmppar ^ notrp8;
|
||||||
|
(where notrp8 is the value of rp8 before those 4 lines).
|
||||||
|
Again a use of the commutative property of xor.
|
||||||
|
Time for a new test!
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 7
|
||||||
|
=========
|
||||||
|
|
||||||
|
The new code now looks like:
|
||||||
|
|
||||||
|
for (i = 0; i < 4; i++)
|
||||||
|
{
|
||||||
|
cur = *bp++; tmppar = cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= tmppar;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp8 ^= tmppar;
|
||||||
|
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
|
||||||
|
|
||||||
|
notrp8 = tmppar;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur;
|
||||||
|
rp8 = rp8 ^ tmppar ^ notrp8;
|
||||||
|
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
|
||||||
|
cur = *bp++; tmppar ^= cur;
|
||||||
|
|
||||||
|
par ^= tmppar;
|
||||||
|
if ((i & 0x1) == 0) rp12 ^= tmppar;
|
||||||
|
if ((i & 0x2) == 0) rp14 ^= tmppar;
|
||||||
|
}
|
||||||
|
rp4 ^= rp4_6;
|
||||||
|
rp6 ^= rp4_6;
|
||||||
|
|
||||||
|
|
||||||
|
Not a big change, but every penny counts :-)
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 7
|
||||||
|
==========
|
||||||
|
|
||||||
|
Acutally this made things worse. Not very much, but I don't want to move
|
||||||
|
into the wrong direction. Maybe something to investigate later. Could
|
||||||
|
have to do with caching again.
|
||||||
|
|
||||||
|
Guess that is what there is to win within the loop. Maybe unrolling one
|
||||||
|
more time will help. I'll keep the optimisations from 7 for now.
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 8
|
||||||
|
=========
|
||||||
|
|
||||||
|
Unrolled the loop one more time.
|
||||||
|
|
||||||
|
|
||||||
|
Analysis 8
|
||||||
|
==========
|
||||||
|
|
||||||
|
This makes things worse. Let's stick with attempt 6 and continue from there.
|
||||||
|
Although it seems that the code within the loop cannot be optimised
|
||||||
|
further there is still room to optimize the generation of the ecc codes.
|
||||||
|
We can simply calcualate the total parity. If this is 0 then rp4 = rp5
|
||||||
|
etc. If the parity is 1, then rp4 = !rp5;
|
||||||
|
But if rp4 = rp5 we do not need rp5 etc. We can just write the even bits
|
||||||
|
in the result byte and then do something like
|
||||||
|
code[0] |= (code[0] << 1);
|
||||||
|
Lets test this.
|
||||||
|
|
||||||
|
|
||||||
|
Attempt 9
|
||||||
|
=========
|
||||||
|
|
||||||
|
Changed the code but again this slightly degrades performance. Tried all
|
||||||
|
kind of other things, like having dedicated parity arrays to avoid the
|
||||||
|
shift after parity[rp7] << 7; No gain.
|
||||||
|
Change the lookup using the parity array by using shift operators (e.g.
|
||||||
|
replace parity[rp7] << 7 with:
|
||||||
|
rp7 ^= (rp7 << 4);
|
||||||
|
rp7 ^= (rp7 << 2);
|
||||||
|
rp7 ^= (rp7 << 1);
|
||||||
|
rp7 &= 0x80;
|
||||||
|
No gain.
|
||||||
|
|
||||||
|
The only marginal change was inverting the parity bits, so we can remove
|
||||||
|
the last three invert statements.
|
||||||
|
|
||||||
|
Ah well, pity this does not deliver more. Then again 10 million
|
||||||
|
iterations using the linux driver code takes between 13 and 13.5
|
||||||
|
seconds, whereas my code now takes about 0.73 seconds for those 10
|
||||||
|
million iterations. So basically I've improved the performance by a
|
||||||
|
factor 18 on my system. Not that bad. Of course on different hardware
|
||||||
|
you will get different results. No warranties!
|
||||||
|
|
||||||
|
But of course there is no such thing as a free lunch. The codesize almost
|
||||||
|
tripled (from 562 bytes to 1434 bytes). Then again, it is not that much.
|
||||||
|
|
||||||
|
|
||||||
|
Correcting errors
|
||||||
|
=================
|
||||||
|
|
||||||
|
For correcting errors I again used the ST application note as a starter,
|
||||||
|
but I also peeked at the existing code.
|
||||||
|
The algorithm itself is pretty straightforward. Just xor the given and
|
||||||
|
the calculated ecc. If all bytes are 0 there is no problem. If 11 bits
|
||||||
|
are 1 we have one correctable bit error. If there is 1 bit 1, we have an
|
||||||
|
error in the given ecc code.
|
||||||
|
It proved to be fastest to do some table lookups. Performance gain
|
||||||
|
introduced by this is about a factor 2 on my system when a repair had to
|
||||||
|
be done, and 1% or so if no repair had to be done.
|
||||||
|
Code size increased from 330 bytes to 686 bytes for this function.
|
||||||
|
(gcc 4.2, -O3)
|
||||||
|
|
||||||
|
|
||||||
|
Conclusion
|
||||||
|
==========
|
||||||
|
|
||||||
|
The gain when calculating the ecc is tremendous. Om my development hardware
|
||||||
|
a speedup of a factor of 18 for ecc calculation was achieved. On a test on an
|
||||||
|
embedded system with a MIPS core a factor 7 was obtained.
|
||||||
|
On a test with a Linksys NSLU2 (ARMv5TE processor) the speedup was a factor
|
||||||
|
5 (big endian mode, gcc 4.1.2, -O3)
|
||||||
|
For correction not much gain could be obtained (as bitflips are rare). Then
|
||||||
|
again there are also much less cycles spent there.
|
||||||
|
|
||||||
|
It seems there is not much more gain possible in this, at least when
|
||||||
|
programmed in C. Of course it might be possible to squeeze something more
|
||||||
|
out of it with an assembler program, but due to pipeline behaviour etc
|
||||||
|
this is very tricky (at least for intel hw).
|
||||||
|
|
||||||
|
Author: Frans Meulenbroeks
|
||||||
|
Copyright (C) 2008 Koninklijke Philips Electronics NV.
|
|
@ -0,0 +1,46 @@
|
||||||
|
Copyright (c) 2003-2008 QLogic Corporation
|
||||||
|
QLogic Linux Networking HBA Driver
|
||||||
|
|
||||||
|
This program includes a device driver for Linux 2.6 that may be
|
||||||
|
distributed with QLogic hardware specific firmware binary file.
|
||||||
|
You may modify and redistribute the device driver code under the
|
||||||
|
GNU General Public License as published by the Free Software
|
||||||
|
Foundation (version 2 or a later version).
|
||||||
|
|
||||||
|
You may redistribute the hardware specific firmware binary file
|
||||||
|
under the following terms:
|
||||||
|
|
||||||
|
1. Redistribution of source code (only if applicable),
|
||||||
|
must retain the above copyright notice, this list of
|
||||||
|
conditions and the following disclaimer.
|
||||||
|
|
||||||
|
2. Redistribution in binary form must reproduce the above
|
||||||
|
copyright notice, this list of conditions and the
|
||||||
|
following disclaimer in the documentation and/or other
|
||||||
|
materials provided with the distribution.
|
||||||
|
|
||||||
|
3. The name of QLogic Corporation may not be used to
|
||||||
|
endorse or promote products derived from this software
|
||||||
|
without specific prior written permission
|
||||||
|
|
||||||
|
REGARDLESS OF WHAT LICENSING MECHANISM IS USED OR APPLICABLE,
|
||||||
|
THIS PROGRAM IS PROVIDED BY QLOGIC CORPORATION "AS IS'' AND ANY
|
||||||
|
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||||
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
|
||||||
|
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR
|
||||||
|
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
||||||
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
|
||||||
|
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||||||
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
||||||
|
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||||||
|
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||||
|
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||||
|
POSSIBILITY OF SUCH DAMAGE.
|
||||||
|
|
||||||
|
USER ACKNOWLEDGES AND AGREES THAT USE OF THIS PROGRAM WILL NOT
|
||||||
|
CREATE OR GIVE GROUNDS FOR A LICENSE BY IMPLICATION, ESTOPPEL, OR
|
||||||
|
OTHERWISE IN ANY INTELLECTUAL PROPERTY RIGHTS (PATENT, COPYRIGHT,
|
||||||
|
TRADE SECRET, MASK WORK, OR OTHER PROPRIETARY RIGHT) EMBODIED IN
|
||||||
|
ANY OTHER QLOGIC HARDWARE OR SOFTWARE EITHER SOLELY OR IN
|
||||||
|
COMBINATION WITH THIS PROGRAM.
|
||||||
|
|
|
@ -35,8 +35,9 @@ This file contains
|
||||||
6.1 general settings
|
6.1 general settings
|
||||||
6.2 local loopback of sent frames
|
6.2 local loopback of sent frames
|
||||||
6.3 CAN controller hardware filters
|
6.3 CAN controller hardware filters
|
||||||
6.4 currently supported CAN hardware
|
6.4 The virtual CAN driver (vcan)
|
||||||
6.5 todo
|
6.5 currently supported CAN hardware
|
||||||
|
6.6 todo
|
||||||
|
|
||||||
7 Credits
|
7 Credits
|
||||||
|
|
||||||
|
@ -584,7 +585,42 @@ solution for a couple of reasons:
|
||||||
@133MHz with four SJA1000 CAN controllers from 2002 under heavy bus
|
@133MHz with four SJA1000 CAN controllers from 2002 under heavy bus
|
||||||
load without any problems ...
|
load without any problems ...
|
||||||
|
|
||||||
6.4 currently supported CAN hardware (September 2007)
|
6.4 The virtual CAN driver (vcan)
|
||||||
|
|
||||||
|
Similar to the network loopback devices, vcan offers a virtual local
|
||||||
|
CAN interface. A full qualified address on CAN consists of
|
||||||
|
|
||||||
|
- a unique CAN Identifier (CAN ID)
|
||||||
|
- the CAN bus this CAN ID is transmitted on (e.g. can0)
|
||||||
|
|
||||||
|
so in common use cases more than one virtual CAN interface is needed.
|
||||||
|
|
||||||
|
The virtual CAN interfaces allow the transmission and reception of CAN
|
||||||
|
frames without real CAN controller hardware. Virtual CAN network
|
||||||
|
devices are usually named 'vcanX', like vcan0 vcan1 vcan2 ...
|
||||||
|
When compiled as a module the virtual CAN driver module is called vcan.ko
|
||||||
|
|
||||||
|
Since Linux Kernel version 2.6.24 the vcan driver supports the Kernel
|
||||||
|
netlink interface to create vcan network devices. The creation and
|
||||||
|
removal of vcan network devices can be managed with the ip(8) tool:
|
||||||
|
|
||||||
|
- Create a virtual CAN network interface:
|
||||||
|
ip link add type vcan
|
||||||
|
|
||||||
|
- Create a virtual CAN network interface with a specific name 'vcan42':
|
||||||
|
ip link add dev vcan42 type vcan
|
||||||
|
|
||||||
|
- Remove a (virtual CAN) network interface 'vcan42':
|
||||||
|
ip link del vcan42
|
||||||
|
|
||||||
|
The tool 'vcan' from the SocketCAN SVN repository on BerliOS is obsolete.
|
||||||
|
|
||||||
|
Virtual CAN network device creation in older Kernels:
|
||||||
|
In Linux Kernel versions < 2.6.24 the vcan driver creates 4 vcan
|
||||||
|
netdevices at module load time by default. This value can be changed
|
||||||
|
with the module parameter 'numdev'. E.g. 'modprobe vcan numdev=8'
|
||||||
|
|
||||||
|
6.5 currently supported CAN hardware
|
||||||
|
|
||||||
On the project website http://developer.berlios.de/projects/socketcan
|
On the project website http://developer.berlios.de/projects/socketcan
|
||||||
there are different drivers available:
|
there are different drivers available:
|
||||||
|
@ -603,7 +639,7 @@ solution for a couple of reasons:
|
||||||
|
|
||||||
Please check the Mailing Lists on the berlios OSS project website.
|
Please check the Mailing Lists on the berlios OSS project website.
|
||||||
|
|
||||||
6.5 todo (September 2007)
|
6.6 todo
|
||||||
|
|
||||||
The configuration interface for CAN network drivers is still an open
|
The configuration interface for CAN network drivers is still an open
|
||||||
issue that has not been finalized in the socketcan project. Also the
|
issue that has not been finalized in the socketcan project. Also the
|
||||||
|
|
|
@ -3,7 +3,7 @@ NOTE
|
||||||
----
|
----
|
||||||
|
|
||||||
This document was contributed by Cirrus Logic for kernel 2.2.5. This version
|
This document was contributed by Cirrus Logic for kernel 2.2.5. This version
|
||||||
has been updated for 2.3.48 by Andrew Morton <andrewm@uow.edu.au>
|
has been updated for 2.3.48 by Andrew Morton.
|
||||||
|
|
||||||
Cirrus make a copy of this driver available at their website, as
|
Cirrus make a copy of this driver available at their website, as
|
||||||
described below. In general, you should use the driver version which
|
described below. In general, you should use the driver version which
|
||||||
|
@ -690,7 +690,7 @@ latest drivers and technical publications.
|
||||||
6.4 Current maintainer
|
6.4 Current maintainer
|
||||||
|
|
||||||
In February 2000 the maintenance of this driver was assumed by Andrew
|
In February 2000 the maintenance of this driver was assumed by Andrew
|
||||||
Morton <akpm@zip.com.au>
|
Morton.
|
||||||
|
|
||||||
6.5 Kernel module parameters
|
6.5 Kernel module parameters
|
||||||
|
|
||||||
|
|
|
@ -24,4 +24,56 @@ netif_{start|stop|wake}_subqueue() functions to manage each queue while the
|
||||||
device is still operational. netdev->queue_lock is still used when the device
|
device is still operational. netdev->queue_lock is still used when the device
|
||||||
comes online or when it's completely shut down (unregister_netdev(), etc.).
|
comes online or when it's completely shut down (unregister_netdev(), etc.).
|
||||||
|
|
||||||
Author: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com>
|
|
||||||
|
Section 2: Qdisc support for multiqueue devices
|
||||||
|
|
||||||
|
-----------------------------------------------
|
||||||
|
|
||||||
|
Currently two qdiscs are optimized for multiqueue devices. The first is the
|
||||||
|
default pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue.
|
||||||
|
A new round-robin qdisc, sch_multiq also supports multiple hardware queues. The
|
||||||
|
qdisc is responsible for classifying the skb's and then directing the skb's to
|
||||||
|
bands and queues based on the value in skb->queue_mapping. Use this field in
|
||||||
|
the base driver to determine which queue to send the skb to.
|
||||||
|
|
||||||
|
sch_multiq has been added for hardware that wishes to avoid head-of-line
|
||||||
|
blocking. It will cycle though the bands and verify that the hardware queue
|
||||||
|
associated with the band is not stopped prior to dequeuing a packet.
|
||||||
|
|
||||||
|
On qdisc load, the number of bands is based on the number of queues on the
|
||||||
|
hardware. Once the association is made, any skb with skb->queue_mapping set,
|
||||||
|
will be queued to the band associated with the hardware queue.
|
||||||
|
|
||||||
|
|
||||||
|
Section 3: Brief howto using MULTIQ for multiqueue devices
|
||||||
|
---------------------------------------------------------------
|
||||||
|
|
||||||
|
The userspace command 'tc,' part of the iproute2 package, is used to configure
|
||||||
|
qdiscs. To add the MULTIQ qdisc to your network device, assuming the device
|
||||||
|
is called eth0, run the following command:
|
||||||
|
|
||||||
|
# tc qdisc add dev eth0 root handle 1: multiq
|
||||||
|
|
||||||
|
The qdisc will allocate the number of bands to equal the number of queues that
|
||||||
|
the device reports, and bring the qdisc online. Assuming eth0 has 4 Tx
|
||||||
|
queues, the band mapping would look like:
|
||||||
|
|
||||||
|
band 0 => queue 0
|
||||||
|
band 1 => queue 1
|
||||||
|
band 2 => queue 2
|
||||||
|
band 3 => queue 3
|
||||||
|
|
||||||
|
Traffic will begin flowing through each queue based on either the simple_tx_hash
|
||||||
|
function or based on netdev->select_queue() if you have it defined.
|
||||||
|
|
||||||
|
The behavior of tc filters remains the same. However a new tc action,
|
||||||
|
skbedit, has been added. Assuming you wanted to route all traffic to a
|
||||||
|
specific host, for example 192.168.0.3, through a specific queue you could use
|
||||||
|
this action and establish a filter such as:
|
||||||
|
|
||||||
|
tc filter add dev eth0 parent 1: protocol ip prio 1 u32 \
|
||||||
|
match ip dst 192.168.0.3 \
|
||||||
|
action skbedit queue_mapping 3
|
||||||
|
|
||||||
|
Author: Alexander Duyck <alexander.h.duyck@intel.com>
|
||||||
|
Original Author: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com>
|
||||||
|
|
|
@ -0,0 +1,175 @@
|
||||||
|
Linux Phonet protocol family
|
||||||
|
============================
|
||||||
|
|
||||||
|
Introduction
|
||||||
|
------------
|
||||||
|
|
||||||
|
Phonet is a packet protocol used by Nokia cellular modems for both IPC
|
||||||
|
and RPC. With the Linux Phonet socket family, Linux host processes can
|
||||||
|
receive and send messages from/to the modem, or any other external
|
||||||
|
device attached to the modem. The modem takes care of routing.
|
||||||
|
|
||||||
|
Phonet packets can be exchanged through various hardware connections
|
||||||
|
depending on the device, such as:
|
||||||
|
- USB with the CDC Phonet interface,
|
||||||
|
- infrared,
|
||||||
|
- Bluetooth,
|
||||||
|
- an RS232 serial port (with a dedicated "FBUS" line discipline),
|
||||||
|
- the SSI bus with some TI OMAP processors.
|
||||||
|
|
||||||
|
|
||||||
|
Packets format
|
||||||
|
--------------
|
||||||
|
|
||||||
|
Phonet packets have a common header as follows:
|
||||||
|
|
||||||
|
struct phonethdr {
|
||||||
|
uint8_t pn_media; /* Media type (link-layer identifier) */
|
||||||
|
uint8_t pn_rdev; /* Receiver device ID */
|
||||||
|
uint8_t pn_sdev; /* Sender device ID */
|
||||||
|
uint8_t pn_res; /* Resource ID or function */
|
||||||
|
uint16_t pn_length; /* Big-endian message byte length (minus 6) */
|
||||||
|
uint8_t pn_robj; /* Receiver object ID */
|
||||||
|
uint8_t pn_sobj; /* Sender object ID */
|
||||||
|
};
|
||||||
|
|
||||||
|
On Linux, the link-layer header includes the pn_media byte (see below).
|
||||||
|
The next 7 bytes are part of the network-layer header.
|
||||||
|
|
||||||
|
The device ID is split: the 6 higher-order bits consitute the device
|
||||||
|
address, while the 2 lower-order bits are used for multiplexing, as are
|
||||||
|
the 8-bit object identifiers. As such, Phonet can be considered as a
|
||||||
|
network layer with 6 bits of address space and 10 bits for transport
|
||||||
|
protocol (much like port numbers in IP world).
|
||||||
|
|
||||||
|
The modem always has address number zero. All other device have a their
|
||||||
|
own 6-bit address.
|
||||||
|
|
||||||
|
|
||||||
|
Link layer
|
||||||
|
----------
|
||||||
|
|
||||||
|
Phonet links are always point-to-point links. The link layer header
|
||||||
|
consists of a single Phonet media type byte. It uniquely identifies the
|
||||||
|
link through which the packet is transmitted, from the modem's
|
||||||
|
perspective. Each Phonet network device shall prepend and set the media
|
||||||
|
type byte as appropriate. For convenience, a common phonet_header_ops
|
||||||
|
link-layer header operations structure is provided. It sets the
|
||||||
|
media type according to the network device hardware address.
|
||||||
|
|
||||||
|
Linux Phonet network interfaces support a dedicated link layer packets
|
||||||
|
type (ETH_P_PHONET) which is out of the Ethernet type range. They can
|
||||||
|
only send and receive Phonet packets.
|
||||||
|
|
||||||
|
The virtual TUN tunnel device driver can also be used for Phonet. This
|
||||||
|
requires IFF_TUN mode, _without_ the IFF_NO_PI flag. In this case,
|
||||||
|
there is no link-layer header, so there is no Phonet media type byte.
|
||||||
|
|
||||||
|
Note that Phonet interfaces are not allowed to re-order packets, so
|
||||||
|
only the (default) Linux FIFO qdisc should be used with them.
|
||||||
|
|
||||||
|
|
||||||
|
Network layer
|
||||||
|
-------------
|
||||||
|
|
||||||
|
The Phonet socket address family maps the Phonet packet header:
|
||||||
|
|
||||||
|
struct sockaddr_pn {
|
||||||
|
sa_family_t spn_family; /* AF_PHONET */
|
||||||
|
uint8_t spn_obj; /* Object ID */
|
||||||
|
uint8_t spn_dev; /* Device ID */
|
||||||
|
uint8_t spn_resource; /* Resource or function */
|
||||||
|
uint8_t spn_zero[...]; /* Padding */
|
||||||
|
};
|
||||||
|
|
||||||
|
The resource field is only used when sending and receiving;
|
||||||
|
It is ignored by bind() and getsockname().
|
||||||
|
|
||||||
|
|
||||||
|
Low-level datagram protocol
|
||||||
|
---------------------------
|
||||||
|
|
||||||
|
Applications can send Phonet messages using the Phonet datagram socket
|
||||||
|
protocol from the PF_PHONET family. Each socket is bound to one of the
|
||||||
|
2^10 object IDs available, and can send and receive packets with any
|
||||||
|
other peer.
|
||||||
|
|
||||||
|
struct sockaddr_pn addr = { .spn_family = AF_PHONET, };
|
||||||
|
ssize_t len;
|
||||||
|
socklen_t addrlen = sizeof(addr);
|
||||||
|
int fd;
|
||||||
|
|
||||||
|
fd = socket(PF_PHONET, SOCK_DGRAM, 0);
|
||||||
|
bind(fd, (struct sockaddr *)&addr, sizeof(addr));
|
||||||
|
/* ... */
|
||||||
|
|
||||||
|
sendto(fd, msg, msglen, 0, (struct sockaddr *)&addr, sizeof(addr));
|
||||||
|
len = recvfrom(fd, buf, sizeof(buf), 0,
|
||||||
|
(struct sockaddr *)&addr, &addrlen);
|
||||||
|
|
||||||
|
This protocol follows the SOCK_DGRAM connection-less semantics.
|
||||||
|
However, connect() and getpeername() are not supported, as they did
|
||||||
|
not seem useful with Phonet usages (could be added easily).
|
||||||
|
|
||||||
|
|
||||||
|
Phonet Pipe protocol
|
||||||
|
--------------------
|
||||||
|
|
||||||
|
The Phonet Pipe protocol is a simple sequenced packets protocol
|
||||||
|
with end-to-end congestion control. It uses the passive listening
|
||||||
|
socket paradigm. The listening socket is bound to an unique free object
|
||||||
|
ID. Each listening socket can handle up to 255 simultaneous
|
||||||
|
connections, one per accept()'d socket.
|
||||||
|
|
||||||
|
int lfd, cfd;
|
||||||
|
|
||||||
|
lfd = socket(PF_PHONET, SOCK_SEQPACKET, PN_PROTO_PIPE);
|
||||||
|
listen (lfd, INT_MAX);
|
||||||
|
|
||||||
|
/* ... */
|
||||||
|
cfd = accept(lfd, NULL, NULL);
|
||||||
|
for (;;)
|
||||||
|
{
|
||||||
|
char buf[...];
|
||||||
|
ssize_t len = read(cfd, buf, sizeof(buf));
|
||||||
|
|
||||||
|
/* ... */
|
||||||
|
|
||||||
|
write(cfd, msg, msglen);
|
||||||
|
}
|
||||||
|
|
||||||
|
Connections are established between two endpoints by a "third party"
|
||||||
|
application. This means that both endpoints are passive; so connect()
|
||||||
|
is not possible.
|
||||||
|
|
||||||
|
WARNING:
|
||||||
|
When polling a connected pipe socket for writability, there is an
|
||||||
|
intrinsic race condition whereby writability might be lost between the
|
||||||
|
polling and the writing system calls. In this case, the socket will
|
||||||
|
block until write becomes possible again, unless non-blocking mode
|
||||||
|
is enabled.
|
||||||
|
|
||||||
|
|
||||||
|
The pipe protocol provides two socket options at the SOL_PNPIPE level:
|
||||||
|
|
||||||
|
PNPIPE_ENCAP accepts one integer value (int) of:
|
||||||
|
|
||||||
|
PNPIPE_ENCAP_NONE: The socket operates normally (default).
|
||||||
|
|
||||||
|
PNPIPE_ENCAP_IP: The socket is used as a backend for a virtual IP
|
||||||
|
interface. This requires CAP_NET_ADMIN capability. GPRS data
|
||||||
|
support on Nokia modems can use this. Note that the socket cannot
|
||||||
|
be reliably poll()'d or read() from while in this mode.
|
||||||
|
|
||||||
|
PNPIPE_IFINDEX is a read-only integer value. It contains the
|
||||||
|
interface index of the network interface created by PNPIPE_ENCAP,
|
||||||
|
or zero if encapsulation is off.
|
||||||
|
|
||||||
|
|
||||||
|
Authors
|
||||||
|
-------
|
||||||
|
|
||||||
|
Linux Phonet was initially written by Sakari Ailus.
|
||||||
|
Other contributors include Mikä Liljeberg, Andras Domokos,
|
||||||
|
Carlos Chinea and Rémi Denis-Courmont.
|
||||||
|
Copyright (C) 2008 Nokia Corporation.
|
|
@ -0,0 +1,194 @@
|
||||||
|
Linux wireless regulatory documentation
|
||||||
|
---------------------------------------
|
||||||
|
|
||||||
|
This document gives a brief review over how the Linux wireless
|
||||||
|
regulatory infrastructure works.
|
||||||
|
|
||||||
|
More up to date information can be obtained at the project's web page:
|
||||||
|
|
||||||
|
http://wireless.kernel.org/en/developers/Regulatory
|
||||||
|
|
||||||
|
Keeping regulatory domains in userspace
|
||||||
|
---------------------------------------
|
||||||
|
|
||||||
|
Due to the dynamic nature of regulatory domains we keep them
|
||||||
|
in userspace and provide a framework for userspace to upload
|
||||||
|
to the kernel one regulatory domain to be used as the central
|
||||||
|
core regulatory domain all wireless devices should adhere to.
|
||||||
|
|
||||||
|
How to get regulatory domains to the kernel
|
||||||
|
-------------------------------------------
|
||||||
|
|
||||||
|
Userspace gets a regulatory domain in the kernel by having
|
||||||
|
a userspace agent build it and send it via nl80211. Only
|
||||||
|
expected regulatory domains will be respected by the kernel.
|
||||||
|
|
||||||
|
A currently available userspace agent which can accomplish this
|
||||||
|
is CRDA - central regulatory domain agent. Its documented here:
|
||||||
|
|
||||||
|
http://wireless.kernel.org/en/developers/Regulatory/CRDA
|
||||||
|
|
||||||
|
Essentially the kernel will send a udev event when it knows
|
||||||
|
it needs a new regulatory domain. A udev rule can be put in place
|
||||||
|
to trigger crda to send the respective regulatory domain for a
|
||||||
|
specific ISO/IEC 3166 alpha2.
|
||||||
|
|
||||||
|
Below is an example udev rule which can be used:
|
||||||
|
|
||||||
|
# Example file, should be put in /etc/udev/rules.d/regulatory.rules
|
||||||
|
KERNEL=="regulatory*", ACTION=="change", SUBSYSTEM=="platform", RUN+="/sbin/crda"
|
||||||
|
|
||||||
|
The alpha2 is passed as an environment variable under the variable COUNTRY.
|
||||||
|
|
||||||
|
Who asks for regulatory domains?
|
||||||
|
--------------------------------
|
||||||
|
|
||||||
|
* Users
|
||||||
|
|
||||||
|
Users can use iw:
|
||||||
|
|
||||||
|
http://wireless.kernel.org/en/users/Documentation/iw
|
||||||
|
|
||||||
|
An example:
|
||||||
|
|
||||||
|
# set regulatory domain to "Costa Rica"
|
||||||
|
iw reg set CR
|
||||||
|
|
||||||
|
This will request the kernel to set the regulatory domain to
|
||||||
|
the specificied alpha2. The kernel in turn will then ask userspace
|
||||||
|
to provide a regulatory domain for the alpha2 specified by the user
|
||||||
|
by sending a uevent.
|
||||||
|
|
||||||
|
* Wireless subsystems for Country Information elements
|
||||||
|
|
||||||
|
The kernel will send a uevent to inform userspace a new
|
||||||
|
regulatory domain is required. More on this to be added
|
||||||
|
as its integration is added.
|
||||||
|
|
||||||
|
* Drivers
|
||||||
|
|
||||||
|
If drivers determine they need a specific regulatory domain
|
||||||
|
set they can inform the wireless core using regulatory_hint().
|
||||||
|
They have two options -- they either provide an alpha2 so that
|
||||||
|
crda can provide back a regulatory domain for that country or
|
||||||
|
they can build their own regulatory domain based on internal
|
||||||
|
custom knowledge so the wireless core can respect it.
|
||||||
|
|
||||||
|
*Most* drivers will rely on the first mechanism of providing a
|
||||||
|
regulatory hint with an alpha2. For these drivers there is an additional
|
||||||
|
check that can be used to ensure compliance based on custom EEPROM
|
||||||
|
regulatory data. This additional check can be used by drivers by
|
||||||
|
registering on its struct wiphy a reg_notifier() callback. This notifier
|
||||||
|
is called when the core's regulatory domain has been changed. The driver
|
||||||
|
can use this to review the changes made and also review who made them
|
||||||
|
(driver, user, country IE) and determine what to allow based on its
|
||||||
|
internal EEPROM data. Devices drivers wishing to be capable of world
|
||||||
|
roaming should use this callback. More on world roaming will be
|
||||||
|
added to this document when its support is enabled.
|
||||||
|
|
||||||
|
Device drivers who provide their own built regulatory domain
|
||||||
|
do not need a callback as the channels registered by them are
|
||||||
|
the only ones that will be allowed and therefore *additional*
|
||||||
|
cannels cannot be enabled.
|
||||||
|
|
||||||
|
Example code - drivers hinting an alpha2:
|
||||||
|
------------------------------------------
|
||||||
|
|
||||||
|
This example comes from the zd1211rw device driver. You can start
|
||||||
|
by having a mapping of your device's EEPROM country/regulatory
|
||||||
|
domain value to to a specific alpha2 as follows:
|
||||||
|
|
||||||
|
static struct zd_reg_alpha2_map reg_alpha2_map[] = {
|
||||||
|
{ ZD_REGDOMAIN_FCC, "US" },
|
||||||
|
{ ZD_REGDOMAIN_IC, "CA" },
|
||||||
|
{ ZD_REGDOMAIN_ETSI, "DE" }, /* Generic ETSI, use most restrictive */
|
||||||
|
{ ZD_REGDOMAIN_JAPAN, "JP" },
|
||||||
|
{ ZD_REGDOMAIN_JAPAN_ADD, "JP" },
|
||||||
|
{ ZD_REGDOMAIN_SPAIN, "ES" },
|
||||||
|
{ ZD_REGDOMAIN_FRANCE, "FR" },
|
||||||
|
|
||||||
|
Then you can define a routine to map your read EEPROM value to an alpha2,
|
||||||
|
as follows:
|
||||||
|
|
||||||
|
static int zd_reg2alpha2(u8 regdomain, char *alpha2)
|
||||||
|
{
|
||||||
|
unsigned int i;
|
||||||
|
struct zd_reg_alpha2_map *reg_map;
|
||||||
|
for (i = 0; i < ARRAY_SIZE(reg_alpha2_map); i++) {
|
||||||
|
reg_map = ®_alpha2_map[i];
|
||||||
|
if (regdomain == reg_map->reg) {
|
||||||
|
alpha2[0] = reg_map->alpha2[0];
|
||||||
|
alpha2[1] = reg_map->alpha2[1];
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
Lastly, you can then hint to the core of your discovered alpha2, if a match
|
||||||
|
was found. You need to do this after you have registered your wiphy. You
|
||||||
|
are expected to do this during initialization.
|
||||||
|
|
||||||
|
r = zd_reg2alpha2(mac->regdomain, alpha2);
|
||||||
|
if (!r)
|
||||||
|
regulatory_hint(hw->wiphy, alpha2, NULL);
|
||||||
|
|
||||||
|
Example code - drivers providing a built in regulatory domain:
|
||||||
|
--------------------------------------------------------------
|
||||||
|
|
||||||
|
If you have regulatory information you can obtain from your
|
||||||
|
driver and you *need* to use this we let you build a regulatory domain
|
||||||
|
structure and pass it to the wireless core. To do this you should
|
||||||
|
kmalloc() a structure big enough to hold your regulatory domain
|
||||||
|
structure and you should then fill it with your data. Finally you simply
|
||||||
|
call regulatory_hint() with the regulatory domain structure in it.
|
||||||
|
|
||||||
|
Bellow is a simple example, with a regulatory domain cached using the stack.
|
||||||
|
Your implementation may vary (read EEPROM cache instead, for example).
|
||||||
|
|
||||||
|
Example cache of some regulatory domain
|
||||||
|
|
||||||
|
struct ieee80211_regdomain mydriver_jp_regdom = {
|
||||||
|
.n_reg_rules = 3,
|
||||||
|
.alpha2 = "JP",
|
||||||
|
//.alpha2 = "99", /* If I have no alpha2 to map it to */
|
||||||
|
.reg_rules = {
|
||||||
|
/* IEEE 802.11b/g, channels 1..14 */
|
||||||
|
REG_RULE(2412-20, 2484+20, 40, 6, 20, 0),
|
||||||
|
/* IEEE 802.11a, channels 34..48 */
|
||||||
|
REG_RULE(5170-20, 5240+20, 40, 6, 20,
|
||||||
|
NL80211_RRF_PASSIVE_SCAN),
|
||||||
|
/* IEEE 802.11a, channels 52..64 */
|
||||||
|
REG_RULE(5260-20, 5320+20, 40, 6, 20,
|
||||||
|
NL80211_RRF_NO_IBSS |
|
||||||
|
NL80211_RRF_DFS),
|
||||||
|
}
|
||||||
|
};
|
||||||
|
|
||||||
|
Then in some part of your code after your wiphy has been registered:
|
||||||
|
|
||||||
|
int r;
|
||||||
|
struct ieee80211_regdomain *rd;
|
||||||
|
int size_of_regd;
|
||||||
|
int num_rules = mydriver_jp_regdom.n_reg_rules;
|
||||||
|
unsigned int i;
|
||||||
|
|
||||||
|
size_of_regd = sizeof(struct ieee80211_regdomain) +
|
||||||
|
(num_rules * sizeof(struct ieee80211_reg_rule));
|
||||||
|
|
||||||
|
rd = kzalloc(size_of_regd, GFP_KERNEL);
|
||||||
|
if (!rd)
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
memcpy(rd, &mydriver_jp_regdom, sizeof(struct ieee80211_regdomain));
|
||||||
|
|
||||||
|
for (i=0; i < num_rules; i++) {
|
||||||
|
memcpy(&rd->reg_rules[i], &mydriver_jp_regdom.reg_rules[i],
|
||||||
|
sizeof(struct ieee80211_reg_rule));
|
||||||
|
}
|
||||||
|
r = regulatory_hint(hw->wiphy, NULL, rd);
|
||||||
|
if (r) {
|
||||||
|
kfree(rd);
|
||||||
|
return r;
|
||||||
|
}
|
||||||
|
|
|
@ -0,0 +1,85 @@
|
||||||
|
Transparent proxy support
|
||||||
|
=========================
|
||||||
|
|
||||||
|
This feature adds Linux 2.2-like transparent proxy support to current kernels.
|
||||||
|
To use it, enable NETFILTER_TPROXY, the socket match and the TPROXY target in
|
||||||
|
your kernel config. You will need policy routing too, so be sure to enable that
|
||||||
|
as well.
|
||||||
|
|
||||||
|
|
||||||
|
1. Making non-local sockets work
|
||||||
|
================================
|
||||||
|
|
||||||
|
The idea is that you identify packets with destination address matching a local
|
||||||
|
socket on your box, set the packet mark to a certain value, and then match on that
|
||||||
|
value using policy routing to have those packets delivered locally:
|
||||||
|
|
||||||
|
# iptables -t mangle -N DIVERT
|
||||||
|
# iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
|
||||||
|
# iptables -t mangle -A DIVERT -j MARK --set-mark 1
|
||||||
|
# iptables -t mangle -A DIVERT -j ACCEPT
|
||||||
|
|
||||||
|
# ip rule add fwmark 1 lookup 100
|
||||||
|
# ip route add local 0.0.0.0/0 dev lo table 100
|
||||||
|
|
||||||
|
Because of certain restrictions in the IPv4 routing output code you'll have to
|
||||||
|
modify your application to allow it to send datagrams _from_ non-local IP
|
||||||
|
addresses. All you have to do is enable the (SOL_IP, IP_TRANSPARENT) socket
|
||||||
|
option before calling bind:
|
||||||
|
|
||||||
|
fd = socket(AF_INET, SOCK_STREAM, 0);
|
||||||
|
/* - 8< -*/
|
||||||
|
int value = 1;
|
||||||
|
setsockopt(fd, SOL_IP, IP_TRANSPARENT, &value, sizeof(value));
|
||||||
|
/* - 8< -*/
|
||||||
|
name.sin_family = AF_INET;
|
||||||
|
name.sin_port = htons(0xCAFE);
|
||||||
|
name.sin_addr.s_addr = htonl(0xDEADBEEF);
|
||||||
|
bind(fd, &name, sizeof(name));
|
||||||
|
|
||||||
|
A trivial patch for netcat is available here:
|
||||||
|
http://people.netfilter.org/hidden/tproxy/netcat-ip_transparent-support.patch
|
||||||
|
|
||||||
|
|
||||||
|
2. Redirecting traffic
|
||||||
|
======================
|
||||||
|
|
||||||
|
Transparent proxying often involves "intercepting" traffic on a router. This is
|
||||||
|
usually done with the iptables REDIRECT target; however, there are serious
|
||||||
|
limitations of that method. One of the major issues is that it actually
|
||||||
|
modifies the packets to change the destination address -- which might not be
|
||||||
|
acceptable in certain situations. (Think of proxying UDP for example: you won't
|
||||||
|
be able to find out the original destination address. Even in case of TCP
|
||||||
|
getting the original destination address is racy.)
|
||||||
|
|
||||||
|
The 'TPROXY' target provides similar functionality without relying on NAT. Simply
|
||||||
|
add rules like this to the iptables ruleset above:
|
||||||
|
|
||||||
|
# iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY \
|
||||||
|
--tproxy-mark 0x1/0x1 --on-port 50080
|
||||||
|
|
||||||
|
Note that for this to work you'll have to modify the proxy to enable (SOL_IP,
|
||||||
|
IP_TRANSPARENT) for the listening socket.
|
||||||
|
|
||||||
|
|
||||||
|
3. Iptables extensions
|
||||||
|
======================
|
||||||
|
|
||||||
|
To use tproxy you'll need to have the 'socket' and 'TPROXY' modules
|
||||||
|
compiled for iptables. A patched version of iptables is available
|
||||||
|
here: http://git.balabit.hu/?p=bazsi/iptables-tproxy.git
|
||||||
|
|
||||||
|
|
||||||
|
4. Application support
|
||||||
|
======================
|
||||||
|
|
||||||
|
4.1. Squid
|
||||||
|
----------
|
||||||
|
|
||||||
|
Squid 3.HEAD has support built-in. To use it, pass
|
||||||
|
'--enable-linux-netfilter' to configure and set the 'tproxy' option on
|
||||||
|
the HTTP listener you redirect traffic to with the TPROXY iptables
|
||||||
|
target.
|
||||||
|
|
||||||
|
For more information please consult the following page on the Squid
|
||||||
|
wiki: http://wiki.squid-cache.org/Features/Tproxy4
|
|
@ -1,5 +1,5 @@
|
||||||
Documentation/networking/vortex.txt
|
Documentation/networking/vortex.txt
|
||||||
Andrew Morton <andrewm@uow.edu.au>
|
Andrew Morton
|
||||||
30 April 2000
|
30 April 2000
|
||||||
|
|
||||||
|
|
||||||
|
@ -11,7 +11,7 @@ The driver was written by Donald Becker <becker@scyld.com>
|
||||||
Don is no longer the prime maintainer of this version of the driver.
|
Don is no longer the prime maintainer of this version of the driver.
|
||||||
Please report problems to one or more of:
|
Please report problems to one or more of:
|
||||||
|
|
||||||
Andrew Morton <akpm@osdl.org>
|
Andrew Morton
|
||||||
Netdev mailing list <netdev@vger.kernel.org>
|
Netdev mailing list <netdev@vger.kernel.org>
|
||||||
Linux kernel mailing list <linux-kernel@vger.kernel.org>
|
Linux kernel mailing list <linux-kernel@vger.kernel.org>
|
||||||
|
|
||||||
|
@ -305,11 +305,6 @@ Donald's wake-on-LAN page:
|
||||||
|
|
||||||
ftp://ftp.3com.com/pub/nic/3c90x/3c90xx2.exe
|
ftp://ftp.3com.com/pub/nic/3c90x/3c90xx2.exe
|
||||||
|
|
||||||
Driver updates and a detailed changelog for the modifications which
|
|
||||||
were made for the 2.3/2,4 series kernel is available at
|
|
||||||
|
|
||||||
http://www.zip.com.au/~akpm/linux/#3c59x-bc
|
|
||||||
|
|
||||||
|
|
||||||
Autonegotiation notes
|
Autonegotiation notes
|
||||||
---------------------
|
---------------------
|
||||||
|
|
|
@ -1,5 +1,11 @@
|
||||||
This file details changes in 2.6 which affect PCMCIA card driver authors:
|
This file details changes in 2.6 which affect PCMCIA card driver authors:
|
||||||
|
|
||||||
|
* New configuration loop helper (as of 2.6.28)
|
||||||
|
By calling pcmcia_loop_config(), a driver can iterate over all available
|
||||||
|
configuration options. During a driver's probe() phase, one doesn't need
|
||||||
|
to use pcmcia_get_{first,next}_tuple, pcmcia_get_tuple_data and
|
||||||
|
pcmcia_parse_tuple directly in most if not all cases.
|
||||||
|
|
||||||
* New release helper (as of 2.6.17)
|
* New release helper (as of 2.6.17)
|
||||||
Instead of calling pcmcia_release_{configuration,io,irq,win}, all that's
|
Instead of calling pcmcia_release_{configuration,io,irq,win}, all that's
|
||||||
necessary now is calling pcmcia_disable_device. As there is no valid
|
necessary now is calling pcmcia_disable_device. As there is no valid
|
||||||
|
|
|
@ -2,17 +2,8 @@ Regulator Machine Driver Interface
|
||||||
===================================
|
===================================
|
||||||
|
|
||||||
The regulator machine driver interface is intended for board/machine specific
|
The regulator machine driver interface is intended for board/machine specific
|
||||||
initialisation code to configure the regulator subsystem. Typical things that
|
initialisation code to configure the regulator subsystem.
|
||||||
machine drivers would do are :-
|
|
||||||
|
|
||||||
1. Regulator -> Device mapping.
|
|
||||||
2. Regulator supply configuration.
|
|
||||||
3. Power Domain constraint setting.
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
1. Regulator -> device mapping
|
|
||||||
==============================
|
|
||||||
Consider the following machine :-
|
Consider the following machine :-
|
||||||
|
|
||||||
Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
|
Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
|
||||||
|
@ -21,81 +12,82 @@ Consider the following machine :-
|
||||||
|
|
||||||
The drivers for consumers A & B must be mapped to the correct regulator in
|
The drivers for consumers A & B must be mapped to the correct regulator in
|
||||||
order to control their power supply. This mapping can be achieved in machine
|
order to control their power supply. This mapping can be achieved in machine
|
||||||
initialisation code by calling :-
|
initialisation code by creating a struct regulator_consumer_supply for
|
||||||
|
each regulator.
|
||||||
|
|
||||||
int regulator_set_device_supply(const char *regulator, struct device *dev,
|
struct regulator_consumer_supply {
|
||||||
const char *supply);
|
struct device *dev; /* consumer */
|
||||||
|
const char *supply; /* consumer supply - e.g. "vcc" */
|
||||||
|
};
|
||||||
|
|
||||||
and is shown with the following code :-
|
e.g. for the machine above
|
||||||
|
|
||||||
regulator_set_device_supply("Regulator-1", devB, "Vcc");
|
static struct regulator_consumer_supply regulator1_consumers[] = {
|
||||||
regulator_set_device_supply("Regulator-2", devA, "Vcc");
|
{
|
||||||
|
.dev = &platform_consumerB_device.dev,
|
||||||
|
.supply = "Vcc",
|
||||||
|
},};
|
||||||
|
|
||||||
|
static struct regulator_consumer_supply regulator2_consumers[] = {
|
||||||
|
{
|
||||||
|
.dev = &platform_consumerA_device.dev,
|
||||||
|
.supply = "Vcc",
|
||||||
|
},};
|
||||||
|
|
||||||
This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
|
This maps Regulator-1 to the 'Vcc' supply for Consumer B and maps Regulator-2
|
||||||
to the 'Vcc' supply for Consumer A.
|
to the 'Vcc' supply for Consumer A.
|
||||||
|
|
||||||
|
Constraints can now be registered by defining a struct regulator_init_data
|
||||||
|
for each regulator power domain. This structure also maps the consumers
|
||||||
|
to their supply regulator :-
|
||||||
|
|
||||||
2. Regulator supply configuration.
|
static struct regulator_init_data regulator1_data = {
|
||||||
==================================
|
.constraints = {
|
||||||
Consider the following machine (again) :-
|
.min_uV = 3300000,
|
||||||
|
.max_uV = 3300000,
|
||||||
Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
|
.valid_modes_mask = REGULATOR_MODE_NORMAL,
|
||||||
|
|
},
|
||||||
+-> [Consumer B @ 3.3V]
|
.num_consumer_supplies = ARRAY_SIZE(regulator1_consumers),
|
||||||
|
.consumer_supplies = regulator1_consumers,
|
||||||
|
};
|
||||||
|
|
||||||
Regulator-1 supplies power to Regulator-2. This relationship must be registered
|
Regulator-1 supplies power to Regulator-2. This relationship must be registered
|
||||||
with the core so that Regulator-1 is also enabled when Consumer A enables it's
|
with the core so that Regulator-1 is also enabled when Consumer A enables it's
|
||||||
supply (Regulator-2).
|
supply (Regulator-2). The supply regulator is set by the supply_regulator_dev
|
||||||
|
field below:-
|
||||||
|
|
||||||
This relationship can be register with the core via :-
|
static struct regulator_init_data regulator2_data = {
|
||||||
|
.supply_regulator_dev = &platform_regulator1_device.dev,
|
||||||
int regulator_set_supply(const char *regulator, const char *regulator_supply);
|
.constraints = {
|
||||||
|
.min_uV = 1800000,
|
||||||
In this example we would use the following code :-
|
.max_uV = 2000000,
|
||||||
|
.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
|
||||||
regulator_set_supply("Regulator-2", "Regulator-1");
|
.valid_modes_mask = REGULATOR_MODE_NORMAL,
|
||||||
|
},
|
||||||
Relationships can be queried by calling :-
|
.num_consumer_supplies = ARRAY_SIZE(regulator2_consumers),
|
||||||
|
.consumer_supplies = regulator2_consumers,
|
||||||
const char *regulator_get_supply(const char *regulator);
|
|
||||||
|
|
||||||
|
|
||||||
3. Power Domain constraint setting.
|
|
||||||
===================================
|
|
||||||
Each power domain within a system has physical constraints on voltage and
|
|
||||||
current. This must be defined in software so that the power domain is always
|
|
||||||
operated within specifications.
|
|
||||||
|
|
||||||
Consider the following machine (again) :-
|
|
||||||
|
|
||||||
Regulator-1 -+-> Regulator-2 --> [Consumer A @ 1.8 - 2.0V]
|
|
||||||
|
|
|
||||||
+-> [Consumer B @ 3.3V]
|
|
||||||
|
|
||||||
This gives us two regulators and two power domains:
|
|
||||||
|
|
||||||
Domain 1: Regulator-2, Consumer B.
|
|
||||||
Domain 2: Consumer A.
|
|
||||||
|
|
||||||
Constraints can be registered by calling :-
|
|
||||||
|
|
||||||
int regulator_set_platform_constraints(const char *regulator,
|
|
||||||
struct regulation_constraints *constraints);
|
|
||||||
|
|
||||||
The example is defined as follows :-
|
|
||||||
|
|
||||||
struct regulation_constraints domain_1 = {
|
|
||||||
.min_uV = 3300000,
|
|
||||||
.max_uV = 3300000,
|
|
||||||
.valid_modes_mask = REGULATOR_MODE_NORMAL,
|
|
||||||
};
|
};
|
||||||
|
|
||||||
struct regulation_constraints domain_2 = {
|
Finally the regulator devices must be registered in the usual manner.
|
||||||
.min_uV = 1800000,
|
|
||||||
.max_uV = 2000000,
|
|
||||||
.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,
|
|
||||||
.valid_modes_mask = REGULATOR_MODE_NORMAL,
|
|
||||||
};
|
|
||||||
|
|
||||||
regulator_set_platform_constraints("Regulator-1", &domain_1);
|
static struct platform_device regulator_devices[] = {
|
||||||
regulator_set_platform_constraints("Regulator-2", &domain_2);
|
{
|
||||||
|
.name = "regulator",
|
||||||
|
.id = DCDC_1,
|
||||||
|
.dev = {
|
||||||
|
.platform_data = ®ulator1_data,
|
||||||
|
},
|
||||||
|
},
|
||||||
|
{
|
||||||
|
.name = "regulator",
|
||||||
|
.id = DCDC_2,
|
||||||
|
.dev = {
|
||||||
|
.platform_data = ®ulator2_data,
|
||||||
|
},
|
||||||
|
},
|
||||||
|
};
|
||||||
|
/* register regulator 1 device */
|
||||||
|
platform_device_register(&wm8350_regulator_devices[0]);
|
||||||
|
|
||||||
|
/* register regulator 2 device */
|
||||||
|
platform_device_register(&wm8350_regulator_devices[1]);
|
||||||
|
|
|
@ -10,11 +10,11 @@ Registration
|
||||||
|
|
||||||
Drivers can register a regulator by calling :-
|
Drivers can register a regulator by calling :-
|
||||||
|
|
||||||
struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
|
struct regulator_dev *regulator_register(struct device *dev,
|
||||||
void *reg_data);
|
struct regulator_desc *regulator_desc);
|
||||||
|
|
||||||
This will register the regulators capabilities and operations the regulator
|
This will register the regulators capabilities and operations to the regulator
|
||||||
core. The core does not touch reg_data (private to regulator driver).
|
core.
|
||||||
|
|
||||||
Regulators can be unregistered by calling :-
|
Regulators can be unregistered by calling :-
|
||||||
|
|
||||||
|
|
|
@ -54,3 +54,21 @@ used to run with "radeonfb" (it's an ATI Radeon mobility). It turns out
|
||||||
that "radeonfb" simply cannot resume that device - it tries to set the
|
that "radeonfb" simply cannot resume that device - it tries to set the
|
||||||
PLL's, and it just _hangs_. Using the regular VGA console and letting X
|
PLL's, and it just _hangs_. Using the regular VGA console and letting X
|
||||||
resume it instead works fine.
|
resume it instead works fine.
|
||||||
|
|
||||||
|
NOTE
|
||||||
|
====
|
||||||
|
pm_trace uses the system's Real Time Clock (RTC) to save the magic number.
|
||||||
|
Reason for this is that the RTC is the only reliably available piece of
|
||||||
|
hardware during resume operations where a value can be set that will
|
||||||
|
survive a reboot.
|
||||||
|
|
||||||
|
Consequence is that after a resume (even if it is successful) your system
|
||||||
|
clock will have a value corresponding to the magic mumber instead of the
|
||||||
|
correct date/time! It is therefore advisable to use a program like ntp-date
|
||||||
|
or rdate to reset the correct date/time from an external time source when
|
||||||
|
using this trace option.
|
||||||
|
|
||||||
|
As the clock keeps ticking it is also essential that the reboot is done
|
||||||
|
quickly after the resume failure. The trace option does not use the seconds
|
||||||
|
or the low order bits of the minutes of the RTC, but a too long delay will
|
||||||
|
corrupt the magic value.
|
||||||
|
|
|
@ -18,10 +18,6 @@ mpc52xx.txt
|
||||||
- Linux 2.6.x on MPC52xx family
|
- Linux 2.6.x on MPC52xx family
|
||||||
mpc52xx-device-tree-bindings.txt
|
mpc52xx-device-tree-bindings.txt
|
||||||
- MPC5200 Device Tree Bindings
|
- MPC5200 Device Tree Bindings
|
||||||
ppc_htab.txt
|
|
||||||
- info about the Linux/PPC /proc/ppc_htab entry
|
|
||||||
smp.txt
|
|
||||||
- use and state info about Linux/PPC on MP machines
|
|
||||||
sound.txt
|
sound.txt
|
||||||
- info on sound support under Linux/PPC
|
- info on sound support under Linux/PPC
|
||||||
zImage_layout.txt
|
zImage_layout.txt
|
||||||
|
|
|
@ -0,0 +1,40 @@
|
||||||
|
* Freescale 83xx and 512x PCI bridges
|
||||||
|
|
||||||
|
Freescale 83xx and 512x SOCs include the same pci bridge core.
|
||||||
|
|
||||||
|
83xx/512x specific notes:
|
||||||
|
- reg: should contain two address length tuples
|
||||||
|
The first is for the internal pci bridge registers
|
||||||
|
The second is for the pci config space access registers
|
||||||
|
|
||||||
|
Example (MPC8313ERDB)
|
||||||
|
pci0: pci@e0008500 {
|
||||||
|
cell-index = <1>;
|
||||||
|
interrupt-map-mask = <0xf800 0x0 0x0 0x7>;
|
||||||
|
interrupt-map = <
|
||||||
|
/* IDSEL 0x0E -mini PCI */
|
||||||
|
0x7000 0x0 0x0 0x1 &ipic 18 0x8
|
||||||
|
0x7000 0x0 0x0 0x2 &ipic 18 0x8
|
||||||
|
0x7000 0x0 0x0 0x3 &ipic 18 0x8
|
||||||
|
0x7000 0x0 0x0 0x4 &ipic 18 0x8
|
||||||
|
|
||||||
|
/* IDSEL 0x0F - PCI slot */
|
||||||
|
0x7800 0x0 0x0 0x1 &ipic 17 0x8
|
||||||
|
0x7800 0x0 0x0 0x2 &ipic 18 0x8
|
||||||
|
0x7800 0x0 0x0 0x3 &ipic 17 0x8
|
||||||
|
0x7800 0x0 0x0 0x4 &ipic 18 0x8>;
|
||||||
|
interrupt-parent = <&ipic>;
|
||||||
|
interrupts = <66 0x8>;
|
||||||
|
bus-range = <0x0 0x0>;
|
||||||
|
ranges = <0x02000000 0x0 0x90000000 0x90000000 0x0 0x10000000
|
||||||
|
0x42000000 0x0 0x80000000 0x80000000 0x0 0x10000000
|
||||||
|
0x01000000 0x0 0x00000000 0xe2000000 0x0 0x00100000>;
|
||||||
|
clock-frequency = <66666666>;
|
||||||
|
#interrupt-cells = <1>;
|
||||||
|
#size-cells = <2>;
|
||||||
|
#address-cells = <3>;
|
||||||
|
reg = <0xe0008500 0x100 /* internal registers */
|
||||||
|
0xe0008300 0x8>; /* config space access registers */
|
||||||
|
compatible = "fsl,mpc8349-pci";
|
||||||
|
device_type = "pci";
|
||||||
|
};
|
|
@ -0,0 +1,40 @@
|
||||||
|
GPIO controllers on MPC8xxx SoCs
|
||||||
|
|
||||||
|
This is for the non-QE/CPM/GUTs GPIO controllers as found on
|
||||||
|
8349, 8572, 8610 and compatible.
|
||||||
|
|
||||||
|
Every GPIO controller node must have #gpio-cells property defined,
|
||||||
|
this information will be used to translate gpio-specifiers.
|
||||||
|
|
||||||
|
Required properties:
|
||||||
|
- compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for
|
||||||
|
83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx.
|
||||||
|
- #gpio-cells : Should be two. The first cell is the pin number and the
|
||||||
|
second cell is used to specify optional parameters (currently unused).
|
||||||
|
- interrupts : Interrupt mapping for GPIO IRQ (currently unused).
|
||||||
|
- interrupt-parent : Phandle for the interrupt controller that
|
||||||
|
services interrupts for this device.
|
||||||
|
- gpio-controller : Marks the port as GPIO controller.
|
||||||
|
|
||||||
|
Example of gpio-controller nodes for a MPC8347 SoC:
|
||||||
|
|
||||||
|
gpio1: gpio-controller@c00 {
|
||||||
|
#gpio-cells = <2>;
|
||||||
|
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
|
||||||
|
reg = <0xc00 0x100>;
|
||||||
|
interrupts = <74 0x8>;
|
||||||
|
interrupt-parent = <&ipic>;
|
||||||
|
gpio-controller;
|
||||||
|
};
|
||||||
|
|
||||||
|
gpio2: gpio-controller@d00 {
|
||||||
|
#gpio-cells = <2>;
|
||||||
|
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
|
||||||
|
reg = <0xd00 0x100>;
|
||||||
|
interrupts = <75 0x8>;
|
||||||
|
interrupt-parent = <&ipic>;
|
||||||
|
gpio-controller;
|
||||||
|
};
|
||||||
|
|
||||||
|
See booting-without-of.txt for details of how to specify GPIO
|
||||||
|
information for devices.
|
|
@ -20,7 +20,7 @@ Required properties:
|
||||||
- compatible : compatible list, contains 2 entries, first is
|
- compatible : compatible list, contains 2 entries, first is
|
||||||
"fsl,CHIP-dma-channel", where CHIP is the processor
|
"fsl,CHIP-dma-channel", where CHIP is the processor
|
||||||
(mpc8349, mpc8350, etc.) and the second is
|
(mpc8349, mpc8350, etc.) and the second is
|
||||||
"fsl,elo-dma-channel"
|
"fsl,elo-dma-channel". However, see note below.
|
||||||
- reg : <registers mapping for channel>
|
- reg : <registers mapping for channel>
|
||||||
- cell-index : dma channel index starts at 0.
|
- cell-index : dma channel index starts at 0.
|
||||||
|
|
||||||
|
@ -82,7 +82,7 @@ Required properties:
|
||||||
- compatible : compatible list, contains 2 entries, first is
|
- compatible : compatible list, contains 2 entries, first is
|
||||||
"fsl,CHIP-dma-channel", where CHIP is the processor
|
"fsl,CHIP-dma-channel", where CHIP is the processor
|
||||||
(mpc8540, mpc8560, etc.) and the second is
|
(mpc8540, mpc8560, etc.) and the second is
|
||||||
"fsl,eloplus-dma-channel"
|
"fsl,eloplus-dma-channel". However, see note below.
|
||||||
- cell-index : dma channel index starts at 0.
|
- cell-index : dma channel index starts at 0.
|
||||||
- reg : <registers mapping for channel>
|
- reg : <registers mapping for channel>
|
||||||
- interrupts : <interrupt mapping for DMA channel IRQ>
|
- interrupts : <interrupt mapping for DMA channel IRQ>
|
||||||
|
@ -125,3 +125,12 @@ Example:
|
||||||
interrupts = <17 2>;
|
interrupts = <17 2>;
|
||||||
};
|
};
|
||||||
};
|
};
|
||||||
|
|
||||||
|
Note on DMA channel compatible properties: The compatible property must say
|
||||||
|
"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel" to be used by the Elo DMA
|
||||||
|
driver (fsldma). Any DMA channel used by fsldma cannot be used by another
|
||||||
|
DMA driver, such as the SSI sound drivers for the MPC8610. Therefore, any DMA
|
||||||
|
channel that should be used for another driver should not use
|
||||||
|
"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel". For the SSI drivers, for
|
||||||
|
example, the compatible property should be "fsl,ssi-dma-channel". See ssi.txt
|
||||||
|
for more information.
|
||||||
|
|
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