A lock ordering issue can cause deadlocks: in framebuffer/console code,
all needed struct fb_info locks are taken before acquire_console_sem(),
in places which need to take console semaphore.
But fb_set_suspend is always called with console semaphore held, and
inside it we call lock_fb_info which gets the fb_info lock, inverse
locking order of what the rest of the code does. This causes a real
deadlock issue, when we write to state fb sysfs attribute (which calls
fb_set_suspend) while a framebuffer is being unregistered by
remove_conflicting_framebuffers, as can be shown by following show
blocked state trace on a test program which loads i915 and runs another
forked processes writing to state attribute:
Test process with semaphore held and trying to get fb_info lock:
..
fb-test2 D 0000000000000000 0 237 228 0x00000000
ffff8800774f3d68 0000000000000082 00000000000135c0 00000000000135c0
ffff880000000000 ffff8800774f3fd8 ffff8800774f3fd8 ffff880076ee4530
00000000000135c0 ffff8800774f3fd8 ffff8800774f2000 00000000000135c0
Call Trace:
[<ffffffff8141287a>] __mutex_lock_slowpath+0x11a/0x1e0
[<ffffffff814142f2>] ? _raw_spin_lock_irq+0x22/0x40
[<ffffffff814123d3>] mutex_lock+0x23/0x50
[<ffffffff8125dfc5>] lock_fb_info+0x25/0x60
[<ffffffff8125e3f0>] fb_set_suspend+0x20/0x80
[<ffffffff81263e2f>] store_fbstate+0x4f/0x70
[<ffffffff812e7f70>] dev_attr_store+0x20/0x30
[<ffffffff811c46b4>] sysfs_write_file+0xd4/0x160
[<ffffffff81155a26>] vfs_write+0xc6/0x190
[<ffffffff81155d51>] sys_write+0x51/0x90
[<ffffffff8100c012>] system_call_fastpath+0x16/0x1b
..
modprobe process stalled because has the fb_info lock (got inside
unregister_framebuffer) but waiting for the semaphore held by the
test process which is waiting to get the fb_info lock:
..
modprobe D 0000000000000000 0 230 218 0x00000000
ffff880077a4d618 0000000000000082 0000000000000001 0000000000000001
ffff880000000000 ffff880077a4dfd8 ffff880077a4dfd8 ffff8800775a2e20
00000000000135c0 ffff880077a4dfd8 ffff880077a4c000 00000000000135c0
Call Trace:
[<ffffffff81411fe5>] schedule_timeout+0x215/0x310
[<ffffffff81058051>] ? get_parent_ip+0x11/0x50
[<ffffffff814130dd>] __down+0x6d/0xb0
[<ffffffff81089f71>] down+0x41/0x50
[<ffffffff810629ac>] acquire_console_sem+0x2c/0x50
[<ffffffff812ca53d>] unbind_con_driver+0xad/0x2d0
[<ffffffff8126f5f7>] fbcon_event_notify+0x457/0x890
[<ffffffff814144ff>] ? _raw_spin_unlock_irqrestore+0x1f/0x50
[<ffffffff81058051>] ? get_parent_ip+0x11/0x50
[<ffffffff8141836d>] notifier_call_chain+0x4d/0x70
[<ffffffff8108a3b8>] __blocking_notifier_call_chain+0x58/0x80
[<ffffffff8108a3f6>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff8125dabb>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff8125e6ac>] unregister_framebuffer+0x7c/0x130
[<ffffffff8125e8b3>] remove_conflicting_framebuffers+0x153/0x180
[<ffffffff8125eef3>] register_framebuffer+0x93/0x2c0
[<ffffffffa0331112>] drm_fb_helper_single_fb_probe+0x252/0x2f0 [drm_kms_helper]
[<ffffffffa03314a3>] drm_fb_helper_initial_config+0x2f3/0x6d0 [drm_kms_helper]
[<ffffffffa03318dd>] ? drm_fb_helper_single_add_all_connectors+0x5d/0x1c0 [drm_kms_helper]
[<ffffffffa037b588>] intel_fbdev_init+0xa8/0x160 [i915]
[<ffffffffa0343d74>] i915_driver_load+0x854/0x12b0 [i915]
[<ffffffffa02f0e7e>] drm_get_pci_dev+0x19e/0x360 [drm]
[<ffffffff8141821d>] ? sub_preempt_count+0x9d/0xd0
[<ffffffffa0386f91>] i915_pci_probe+0x15/0x17 [i915]
[<ffffffff8124481f>] local_pci_probe+0x5f/0xd0
[<ffffffff81244f89>] pci_device_probe+0x119/0x120
[<ffffffff812eccaa>] ? driver_sysfs_add+0x7a/0xb0
[<ffffffff812ed003>] driver_probe_device+0xa3/0x290
[<ffffffff812ed1f0>] ? __driver_attach+0x0/0xb0
[<ffffffff812ed29b>] __driver_attach+0xab/0xb0
[<ffffffff812ed1f0>] ? __driver_attach+0x0/0xb0
[<ffffffff812ebd3e>] bus_for_each_dev+0x5e/0x90
[<ffffffff812ecc2e>] driver_attach+0x1e/0x20
[<ffffffff812ec6f2>] bus_add_driver+0xe2/0x320
[<ffffffffa03aa000>] ? i915_init+0x0/0x96 [i915]
[<ffffffff812ed536>] driver_register+0x76/0x140
[<ffffffffa03aa000>] ? i915_init+0x0/0x96 [i915]
[<ffffffff81245216>] __pci_register_driver+0x56/0xd0
[<ffffffffa02f1264>] drm_pci_init+0xe4/0xf0 [drm]
[<ffffffffa03aa000>] ? i915_init+0x0/0x96 [i915]
[<ffffffffa02e84a8>] drm_init+0x58/0x70 [drm]
[<ffffffffa03aa094>] i915_init+0x94/0x96 [i915]
[<ffffffff81002194>] do_one_initcall+0x44/0x190
[<ffffffff810a066b>] sys_init_module+0xcb/0x210
[<ffffffff8100c012>] system_call_fastpath+0x16/0x1b
..
fb-test2 which reproduces above is available on kernel.org bug #26232.
To solve this issue, avoid calling lock_fb_info inside fb_set_suspend,
and move it out to where needed (callers of fb_set_suspend must call
lock_fb_info before if needed). So far, the only place which needs to
call lock_fb_info is store_fbstate, all other places which calls
fb_set_suspend are suspend/resume hooks that should not need the lock as
they should be run only when processes are already frozen in
suspend/resume.
References: https://bugzilla.kernel.org/show_bug.cgi?id=26232
Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: stable@kernel.org
The -rt patches change the console_semaphore to console_mutex. As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()
This commit makes things use more neutral function names which dont make
implications about the underlying lock.
The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()
This patch also paves the way to switching console_sem from a semaphore to
a mutex.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It removes a hack from nouveau code which had to detect which
region to pass to kick vesafb/efifb.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
This reverts commit 4148df9b0f.
Let's hope that the mm_lock initialization is now correct with all
drivers, following Krzysztof's patches.
Requested-by: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This way they'll be properly initialized early enough for users that may
touch them before the framebuffer has been registered.
Drivers that allocate their fb_info structure some other way (like
matrocfb's broken static allocation) need to be fixed up appropriately.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
show_pan will display the value of the xoffset twice, instead of the xoffset
and yoffset. Fix.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fb_info->bl_mutex is badly thought out and the backlight class doesn't
need it if the framebuffer/backlight register/unregister order is
consistent, particularly after the backlight locking fixes.
Fix the drivers to use the order:
backlight_device_register()
register_framebuffer()
unregister_framebuffer()
backlight_device_unregister()
and turn bl_mutex into a lock for the bl_curve data only.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
fbdev modedb: make more input and output pointer parameters const
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Check the return value of device_create_file(). If return is 'fail', remove
attributes by calling device_remove_file().
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Seems like not all drivers use the framebuffer_alloc() function and won't
have an initialized mutex. But those don't have a backlight, anyway.
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Daniel R Thompson <daniel.thompson@st.com>
Cc: Jon Smirl <jonsmirl@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order for this feature to work, an interface will be needed. The most
appropriate is sysfs. However, the framebuffer console has no sysfs entry
yet. This will create a sysfs class device entry for fbcon under
/sys/class/graphics.
Add a class_device entry 'fbcon' under class 'graphics'. Console-specific
attributes which where previously under class/graphics/fb[x] are moved to
class/graphics/fbcon. These attributes, 'con_rotate' and 'con_rotate_all',
are also renamed to 'rotate' and 'rotate_all' respectively.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modify the sysfs description of a video mode such that modes are tagged with
their scan type, (p)rogessive, (i)nterlaced, (d)ouble scan. For example,
U:1920x1080i-50. This is useful to disambiguate some of the 'consumer' video
timings found in CEA-861 (especially those for EDTV).
Signed-off-by: Daniel R Thompson <daniel.thompson@st.com>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers. Backward compatibility is retained. A sysfs
interface allows userland to control the brightness with more steps than
before. Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.
[akpm@osdl.org: add needed exports]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A set of 3 small bugfixes, all of which are related to bogus return values
of fb colormap-setting functions.
First, fb_alloc_cmap returns -1 if memory allocation fails. This is a hard
condition to reproduce since you'd have to be really low on memory, but from
studying the contexts in which it is called, I think this function should be
returning a negative errno, and the -1 will be seen as an EPERM. Switching it
to -ENOMEM makes sense.
Second, the store_cmap function which is called for writes to
/sys/class/graphics/fb0/color_map returns 0 for success, but it should be
returning the count of bytes written since its return value ends up in
userspace as the result of the write() syscall.
Third, radeonfb returns 1 instead of a negative errno when FBIOPUTCMAP is
called with an oversized colormap. This is seen in userspace as a return
value of 1 from the ioctl() syscall with errno left unchanged. A more
useful return value would be -EINVAL.
Signed-off-by: Alan Curry <pacman@TheWorld.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add ability to set rotation via sysfs. The attributes are located in
/sys/class/graphics/fb[n] and accepts 0 - unrotated; 1 - clockwise; 2 - upside
down; 3 - counterclockwise.
The attributes are:
con_rotate (r/w) - set rotation of the active console
con_rotate_all (w) - set rotation of all consoles
rotate (r/w) - set rotation of the framebuffer, if supported.
Currently, none of the drivers support this.
This is probably temporary, since con_rotate and con_rotate_all are
console-specific and has no business being under the fb device. However,
until the console layer acquires it's own sysfs class, these attributes will
temporarily reside here.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This small patch returns the stride/line length of the framebuffer via
sysfs.
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch displays the name of the fbdev driver in sysfs.
Down the road this will replace the current proc handle we have.
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Color maps have up to 256 entries. 4096/256 allows for 16 characters per
line. The format for a cmap entry is "%02x%c%4x%4x%4x\n" %02x entry %c
transp %4x red %4x blue %4x green
You can read the color_map with cat fb0/color_map.
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Correctly test for a null pointer before going and dereferencing it.
This defect was found automatically by Coverity Prevent, a static analysis
tool.
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: <linux-fbdev-devel@lists.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It prints out x,x instead of x,y.
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@hotpop.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes some needlessly global identifiers static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Arjan van de Ven <arjanv@infradead.org>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Herton Ronaldo Krzesinski
Lucas De Marchi
Torben Hohn
Marcin Slusarz
Tejun Heo
Linus Torvalds
Paul Mundt
Antonino A. Daplas
Richard Purdie
Geert Uytterhoeven
Greg Kroah-Hartman
Michael Hanselmann
Daniel R Thompson
Jon Smirl
Alan Curry
Matthew Garrett
James Simmons
KAMBAROV, ZAUR
Adrian Bunk
Linus Torvalds