Граф коммитов

225 Коммитов

Автор SHA1 Сообщение Дата
Ilpo Järvinen 16e3238047 serial: 8250: fix XOFF/XON sending when DMA is used
[ Upstream commit f58c252e30 ]

When 8250 UART is using DMA, x_char (XON/XOFF) is never sent
to the wire. After this change, x_char is injected correctly.

Create uart_xchar_out() helper for sending the x_char out and
accounting related to it. It seems that almost every driver
does these same steps with x_char. Except for 8250, however,
almost all currently lack .serial_out so they cannot immediately
take advantage of this new helper.

The downside of this patch is that it might reintroduce
the problems some devices faced with mixed DMA/non-DMA transfer
which caused revert f967fc8f16 (Revert "serial: 8250_dma:
don't bother DMA with small transfers"). However, the impact
should be limited to cases with XON/XOFF (that didn't work
with DMA capable devices to begin with so this problem is not
very likely to cause a major issue, if any at all).

Fixes: 9ee4b83e51 ("serial: 8250: Add support for dmaengine")
Reported-by: Gilles Buloz <gilles.buloz@kontron.com>
Tested-by: Gilles Buloz <gilles.buloz@kontron.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:23:50 +02:00
Johan Hovold 853a9ae29e serial: 8250: fix handle_irq locking
The 8250 handle_irq callback is not just called from the interrupt
handler but also from a timer callback when polling (e.g. for ports
without an interrupt line). Consequently the callback must explicitly
disable interrupts to avoid a potential deadlock with another interrupt
in polled mode.

Add back an irqrestore-version of the sysrq port-unlock helper and use
it in the 8250 callbacks that need it.

Fixes: 75f4e830fa ("serial: do not restore interrupt state in sysrq helper")
Cc: stable@vger.kernel.org	# 5.13
Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210714080427.28164-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-21 12:53:26 +02:00
Jiri Slaby b8be5db573 tty/serial: clean up uart_match_port
* make parameters const (as they are only read)
* return bool (as comparison results are returned)
* add \n before final return

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210519072153.3859-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 16:59:14 +02:00
Jiri Slaby 6e94dbc7a4 tty: cumulate and document tty_struct::flow* members
Group the flow flags under a single struct called flow. The new struct
contains 'stopped' and 'tco_stopped' bools which used to be bits in a
bitfield. The struct also contains the lock protecting them to
potentially share the same cache line.

Note that commit c545b66c69 (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::unused) is aligned to a 8B boundary too and occupies some
bytes from the next word.

So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
   pads the end.

This is also the perfect time to start the documentation of tty_struct
where all this lives. So we start by documenting what these bools
actually serve for. And why we do all the alignment dances. Only the few
up-to-date information from the Theodore's comment made it into this new
Kerneldoc comment.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 16:57:16 +02:00
Johan Hovold 75f4e830fa serial: do not restore interrupt state in sysrq helper
The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.

Since commit 81e2073c17 ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.

Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.

Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Johan Hovold 76437b340b earlycon: drop semicolon from earlycon macro
Drop the trailing semicolon from the OF_EARLYCON_DECLARE() macro
definition which was left when removing the array-of-pointer
indirection.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20201207091601.5202-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-07 10:40:32 +01:00
Johan Hovold 62dcd9c59f earlycon: simplify earlycon-table implementation
Instead of using the array-of-pointers trick to avoid having gcc mess up
the earlycon array stride, specify type alignment when declaring entries
to prevent gcc from increasing alignment.

This is essentially an alternative (one-line) fix to the problem
addressed by commit dd709e72cb ("earlycon: Use a pointer table to fix
__earlycon_table stride").

gcc can increase the alignment of larger objects with static extent as
an optimisation, but this can be suppressed by using the aligned
attribute when declaring variables.

Note that we have been relying on this behaviour for kernel parameters
for 16 years and it indeed hasn't changed since the introduction of the
aligned attribute in gcc-3.1.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20201123102319.8090-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-04 15:49:48 +01:00
Joe Perches 33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Johan Hovold e0830dbf71 serial: core: fix console port-lock regression
Fix the port-lock initialisation regression introduced by commit
a3cb39d258 ("serial: core: Allow detach and attach serial device for
console") by making sure that the lock is again initialised during
console setup.

The console may be registered before the serial controller has been
probed in which case the port lock needs to be initialised during
console setup by a call to uart_set_options(). The console-detach
changes introduced a regression in several drivers by effectively
removing that initialisation by not initialising the lock when the port
is used as a console (which is always the case during console setup).

Add back the early lock initialisation and instead use a new
console-reinit flag to handle the case where a console is being
re-attached through sysfs.

The question whether the console-detach interface should have been added
in the first place is left for another discussion.

Note that the console-enabled check in uart_set_options() is not
redundant because of kgdboc, which can end up reinitialising an already
enabled console (see commit 42b6a1baa3 ("serial_core: Don't
re-initialize a previously initialized spinlock.")).

Fixes: a3cb39d258 ("serial: core: Allow detach and attach serial device for console")
Cc: stable <stable@vger.kernel.org>     # 5.7
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200909143101.15389-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-16 13:22:44 +02:00
Greg Kroah-Hartman 6f2c6599ba Linux 5.8-rc6
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl8UzA4eHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGQ7cH/3v+Gv+SmHJCvaT2
 CSu0+7okVnYbY3UTb3hykk7/aOqb6284KjxR03r0CWFzsEsZVhC5pvvruASSiMQg
 Pi04sLqv6CsGLHd1n+pl4AUYEaxq6k4KS3uU3HHSWxrahDDApQoRUx2F8lpOxyj8
 RiwnoO60IMPA7IFJqzcZuFqsgdxqiiYvnzT461KX8Mrw6fyMXeR2KAj2NwMX8dZN
 At21Sf8+LSoh6q2HnugfiUd/jR10XbfxIIx2lXgIinb15GXgWydEQVrDJ7cUV7ix
 Jd0S+dtOtp+lWtFHDoyjjqqsMV7+G8i/rFNZoxSkyZqsUTaKzaR6JD3moSyoYZgG
 0+eXO4A=
 =9EpR
 -----END PGP SIGNATURE-----

Merge 5.8-rc6 into tty-next

We need the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-20 09:39:11 +02:00
Johan Hovold 225385657b serial: core: drop redundant sysrq checks
The sysrq timestamp will never be set unless port->has_sysrq is set (see
uart_handle_break()) so drop the redundant checks that were added by
commit 1997e9dfdc ("serial_core: Un-ifdef sysrq SUPPORT_SYSRQ").

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20200610152232.16925-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27 16:16:37 +02:00
Johan Hovold 08d5470308 serial: core: fix sysrq overhead regression
Commit 8e20fc3917 ("serial_core: Move sysrq functions from header
file") converted the inline sysrq helpers to exported functions which
are now called for every received character, interrupt and break signal
also on systems without CONFIG_MAGIC_SYSRQ_SERIAL instead of being
optimised away by the compiler.

Inlining these helpers again also avoids the function call overhead when
CONFIG_MAGIC_SYSRQ_SERIAL is enabled (e.g. when the port is not used as
a console).

Fixes: 8e20fc3917 ("serial_core: Move sysrq functions from header file")
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20200610152232.16925-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27 16:16:37 +02:00
Johan Hovold 10652a9e9f Revert "serial: core: Refactor uart_unlock_and_check_sysrq()"
This reverts commit da9a5aa340.

In order to ease backporting a fix for a sysrq regression, revert this
rewrite which was since added on top.

The other sysrq helpers now bail out early when sysrq is not enabled;
it's better to keep that pattern here as well.

Note that the __releases() attribute won't be needed after the follow-on
fix either.

Fixes: da9a5aa340 ("serial: core: Refactor uart_unlock_and_check_sysrq()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200610152232.16925-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27 16:16:37 +02:00
Johan Hovold 167cbce274 serial: core: drop unnecessary gpio include
Drop the recently added gpio include from the serial-core header in
favour of a forward declaration and instead include the gpio header only
where needed.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20200610155121.14014-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27 16:12:45 +02:00
Lukas Wunner d58a2df3d8 serial: 8250: Support rs485 bus termination GPIO
Commit e8759ad17d ("serial: uapi: Add support for bus termination")
introduced the ability to enable rs485 bus termination from user space.
So far the feature is only used by a single driver, 8250_exar.c, using a
hardcoded GPIO pin specific to Siemens IOT2040 products.

Provide for a more generic solution by allowing specification of an
rs485 bus termination GPIO pin in the device tree:  Amend the serial
core to retrieve the GPIO from the device tree (or ACPI table) and amend
the default ->rs485_config() callback for 8250 drivers to change the
GPIO on request from user space.

Perhaps 8250_exar.c can be converted to the generic approach in a
follow-up patch.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-29 12:42:54 +02:00
Lukas Wunner c150c0f362 serial: Allow uart_get_rs485_mode() to return errno
We're about to amend uart_get_rs485_mode() to support a GPIO pin for
rs485 bus termination.  Retrieving the GPIO descriptor may fail, so
allow uart_get_rs485_mode() to return an errno and change all callers
to check for failure.

The GPIO descriptor is going to be stored in struct uart_port.  Pass
that struct to uart_get_rs485_mode() in lieu of a struct device and
struct serial_rs485, both of which are directly accessible from struct
uart_port.

A few drivers call uart_get_rs485_mode() before setting the struct
device pointer in struct uart_port.  Shuffle those calls around where
necessary.

[Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.]

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15 14:47:05 +02:00
Andy Shevchenko da9a5aa340 serial: core: Refactor uart_unlock_and_check_sysrq()
Refactor uart_unlock_and_check_sysrq() to:

  - explicitly show that we release a port lock which makes
    static analyzers happy:

CHECK   drivers/tty/serial/serial_core.c
.../serial_core.c:3290:17: warning: context imbalance in 'uart_unlock_and_check_sysrq' - unexpected unlock

  - use flags instead of irqflags to avoid confusion with IRQ flags

  - provide one return point

  - be more compact

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20200310174337.74109-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12 17:16:42 +01:00
Dmitry Safonov 68af43173d serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE
Many embedded boards have a disconnected TTL level serial which can
generate some garbage that can lead to spurious false sysrq detects.

Currently, sysrq can be either completely disabled for serial console
or always disabled (with CONFIG_MAGIC_SYSRQ_SERIAL), since
commit 732dbf3a61 ("serial: do not accept sysrq characters via serial port")

At Arista, we have such boards that can generate BREAK and random
garbage. While disabling sysrq for serial console would solve
the problem with spurious false sysrq triggers, it's also desirable
to have a way to enable sysrq back.

As a measure of balance between on and off options, add
MAGIC_SYSRQ_SERIAL_SEQUENCE which is a string sequence that can enable
sysrq if it follows BREAK on a serial line. The longer the string - the
less likely it may be in the garbage.

Having the way to enable sysrq was beneficial to debug lockups with
a manual investigation in field and on the other side preventing false
sysrq detections.

Based-on-patch-by: Vasiliy Khoruzhick <vasilykh@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200302175135.269397-3-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-07 09:52:02 +01:00
Dmitry Safonov 7788f549ed serial_core: Remove unused member in uart_port
It should remove the align-padding before @name.

[yes, there's a "hole" in the structure now, but that's fine, no one
cares.  If they do care, the whole thing should be restructured using
pahole to find a better ordering.  Removing this field is good as some
drivers have been known to abuse it for other things when they shouldn't
have been doing that. -- gregkh]

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200114171912.261787-4-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-15 13:39:14 +01:00
Dmitry Safonov 8e20fc3917 serial_core: Move sysrq functions from header file
It's not worth to have them in every serial driver and I'm about to add
another helper function.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200109215444.95995-2-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-10 17:48:02 +01:00
Dmitry Safonov 82cfd2e62b serial_core: Remove SUPPORT_SYSRQ ifdeffery
No one defines it anymore.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-55-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-18 15:05:11 +01:00
Dmitry Safonov 1997e9dfdc serial_core: Un-ifdef sysrq SUPPORT_SYSRQ
The SUPPORT_SYSRQ is messy: every .c source should define it before
including "serial_core.h" if sysrq is supported or struct uart_port will
differ in sizes. Also this prevents moving to serial_core.c functions:
uart_handle_sysrq_char(), uart_prepare_sysrq_char(),
uart_unlock_and_check_sysrq().

It doesn't save many bytes in the structure, and a better way to reduce
it's size would be making rs485 and iso7816 pointers.

Introduce `has_sysrq` member to be used by serial line drivers further.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-4-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 15:10:17 +01:00
Dmitry Safonov 7e5ed9f5e0 serial: Move sysrq members above
At the current place members those follow are:
:	upf_t			flags;
:	upstat_t		status;
:	int			hw_stopped;
:	unsigned int		mctrl;
:	unsigned int		timeout;
:	unsigned int		type;
:	const struct uart_ops	*ops;

Together, they give (*ops) 8-byte align on 64-bit platforms.
And `sysrq_ch` introduces 4-byte padding.

On the other side, above:
:	struct device		*dev;
:	unsigned char		hub6;
:	unsigned char		suspended;
:	unsigned char		unused[2];
:	const char		*name;

Adds another 4-byte padding.

Moving sysrq members just before `hub6` allows to save 8 bytes
per-uart_port on 64-bit platforms:
On my gcc, x86_64 sizeof(struct uart_port) goes from 528 to 520.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-3-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 14:48:51 +01:00
Mauro Carvalho Chehab 65388dad1b docs: serial: move it to the driver-api
The contents of this directory is mostly driver-api stuff.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:03 -03:00
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Mauro Carvalho Chehab f137401780 docs: serial: convert docs to ReST and rename to *.rst
The converted files are focused at the Kernel internal API,
so, this is a good candidate for the kernel API set of books.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 11:37:42 +02:00
Douglas Anderson 3e6f880683 serial: core: Include console.h from serial_core.h
In the static inline function uart_handle_break() in serial_core.h we
dereference port->cons.  That gives an error unless console.h is also
included.

This error hasn't shown up till now because everyone who has defined
SUPPORT_SYSRQ has also included console.h, but it's a bit ugly to make
this requirement.  Let's make the include explicit.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09 09:07:17 -08:00
Douglas Anderson d6e1935819 serial: core: Allow processing sysrq at port unlock time
Right now serial drivers process sysrq keys deep in their character
receiving code.  This means that they've already grabbed their
port->lock spinlock.  This can end up getting in the way if we've go
to do serial stuff (especially kgdb) in response to the sysrq.

Serial drivers have various hacks in them to handle this.  Looking at
'8250_port.c' you can see that the console_write() skips locking if
we're in the sysrq handler.  Looking at 'msm_serial.c' you can see
that the port lock is dropped around uart_handle_sysrq_char().

It turns out that these hacks aren't exactly perfect.  If you have
lockdep turned on and use something like the 8250_port hack you'll get
a splat that looks like:

  WARNING: possible circular locking dependency detected
  [...] is trying to acquire lock:
  ... (console_owner){-.-.}, at: console_unlock+0x2e0/0x5e4

  but task is already holding lock:
  ... (&port_lock_key){-.-.}, at: serial8250_handle_irq+0x30/0xe4

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (&port_lock_key){-.-.}:
         _raw_spin_lock_irqsave+0x58/0x70
         serial8250_console_write+0xa8/0x250
         univ8250_console_write+0x40/0x4c
         console_unlock+0x528/0x5e4
         register_console+0x2c4/0x3b0
         uart_add_one_port+0x350/0x478
         serial8250_register_8250_port+0x350/0x3a8
         dw8250_probe+0x67c/0x754
         platform_drv_probe+0x58/0xa4
         really_probe+0x150/0x294
         driver_probe_device+0xac/0xe8
         __driver_attach+0x98/0xd0
         bus_for_each_dev+0x84/0xc8
         driver_attach+0x2c/0x34
         bus_add_driver+0xf0/0x1ec
         driver_register+0xb4/0x100
         __platform_driver_register+0x60/0x6c
         dw8250_platform_driver_init+0x20/0x28
	 ...

  -> #0 (console_owner){-.-.}:
         lock_acquire+0x1e8/0x214
         console_unlock+0x35c/0x5e4
         vprintk_emit+0x230/0x274
         vprintk_default+0x7c/0x84
         vprintk_func+0x190/0x1bc
         printk+0x80/0xa0
         __handle_sysrq+0x104/0x21c
         handle_sysrq+0x30/0x3c
         serial8250_read_char+0x15c/0x18c
         serial8250_rx_chars+0x34/0x74
         serial8250_handle_irq+0x9c/0xe4
         dw8250_handle_irq+0x98/0xcc
         serial8250_interrupt+0x50/0xe8
         ...

  other info that might help us debug this:

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&port_lock_key);
                                 lock(console_owner);
                                 lock(&port_lock_key);
    lock(console_owner);

   *** DEADLOCK ***

The hack used in 'msm_serial.c' doesn't cause the above splats but it
seems a bit ugly to unlock / lock our spinlock deep in our irq
handler.

It seems like we could defer processing the sysrq until the end of the
interrupt handler right after we've unlocked the port.  With this
scheme if a whole batch of sysrq characters comes in one irq then we
won't handle them all, but that seems like it should be a fine
compromise.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09 09:07:17 -08:00
Greg Kroah-Hartman 817e9bc8cc Revert "serial:serial_core: Allow use of CTS for PPS line discipline"
This reverts commit c550f01c81.

Turns out the samsung tty driver is mucking around in the "unused" port
fields and this patch breaks that code :(

So we need to fix that driver up before this can be accepted.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-04 09:57:45 -07:00
Nicolas Ferre ad8c0eaa0a tty/serial_core: add ISO7816 infrastructure
Add the ISO7816 ioctl and associated accessors and data structure.
Drivers can then use this common implementation to handle ISO7816
(smart cards).

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 13:38:55 -07:00
Steve Sakoman c550f01c81 serial:serial_core: Allow use of CTS for PPS line discipline
Add a "pps_4wire" file to serial ports in sysfs in case the kernel is
configured with CONFIG_PPS_CLIENT_LDISC. Writing 1 to the file enables
the use of CTS instead of DCD for PPS signal input. This is necessary
in case a serial port is not completely wired.
Though this affects PPS processing the patch is against the serial core
as the source of the serial port PPS event dispatching has to be
modified. Furthermore it should be possible to modify the source of
serial port PPS event dispatching before changing the line discipline.

Signed-off-by: Andreas Steinmetz <ast@domdv.de>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Tested-by: Steve Sakoman <steve@sakoman.com>
Tested-by: Eric Gallimore <egallimore@ucsd.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 13:38:55 -07:00
Jisheng Zhang 0238d2b4a4 serial: 8250: introduce get_divisor() and set_divisor() hook
Add these two hooks so that they can be overridden with driver specific
implementations.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-12 17:07:26 +02:00
Greg Kroah-Hartman 7b6c81f46c Merge 4.17-rc3 into tty-next
We want the tty and serial driver fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-30 05:14:55 -07:00
Douglas Anderson c1c734cb1f serial: core: Make sure compiler barfs for 16-byte earlycon names
As part of bringup I ended up wanting to call an earlycon driver by a
name that was exactly 16-bytes big, specifically "qcom_geni_serial".

Unfortunately, when I tried this I found that things compiled just
fine.  They just didn't work.

Specifically the compiler felt perfectly justified in initting the
".name" field of "struct earlycon_id" with the full 16-bytes and just
skipping the '\0'.  Needless to say, that behavior didn't seem ideal,
but I guess someone must have allowed it for a reason.

One way to fix this is to shorten the name field to 15 bytes and then
add an extra byte after that nobody touches.  This should always be
initted to 0 and we're golden.

There are, of course, other ways to fix this too.  We could audit all
the users of the "name" field and make them stop at both null
termination or at 16 bytes.  We could also just make the name field
much bigger so that we're not likely to run into this.  ...but both
seem like we'll just hit the bug again.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 12:31:13 +02:00
Jeremy Kerr c5f78b1fe4 serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOs
This change adds a flag to indicate that a UART is has an external means
of synchronising its FIFO, without needing CTSRTS or XON/XOFF.

This allows us to use the throttle/unthrottle callbacks, without having
to claim other methods of flow control.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:16:50 +02:00
Daniel Kurtz dd709e72cb earlycon: Use a pointer table to fix __earlycon_table stride
Commit 99492c39f3 ("earlycon: Fix __earlycon_table stride") tried to fix
__earlycon_table stride by forcing the earlycon_id struct alignment to 32
and asking the linker to 32-byte align the __earlycon_table symbol.  This
fix was based on commit 07fca0e57f ("tracing: Properly align linker
defined symbols") which tried a similar fix for the tracing subsystem.

However, this fix doesn't quite work because there is no guarantee that
gcc will place structures packed into an array format.  In fact, gcc 4.9
chooses to 64-byte align these structs by inserting additional padding
between the entries because it has no clue that they are supposed to be in
an array.  If we are unlucky, the linker will assign symbol
"__earlycon_table" to a 32-byte aligned address which does not correspond
to the 64-byte aligned contents of section "__earlycon_table".

To address this same problem, the fix to the tracing system was
subsequently re-implemented using a more robust table of pointers approach
by commits:
 3d56e331b6 ("tracing: Replace syscall_meta_data struct array with pointer array")
 6549864629 ("tracepoints: Fix section alignment using pointer array")
 e4a9ea5ee7 ("tracing: Replace trace_event struct array with pointer array")

Let's use this same "array of pointers to structs" approach for
EARLYCON_TABLE.

Fixes: 99492c39f3 ("earlycon: Fix __earlycon_table stride")
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Suggested-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 10:06:59 +02:00
Mathieu Malaterre 219c7b06f3 powerpc: Mark the variable earlycon_acpi_spcr_enable maybe_unused
Re-use the object-like macro EARLYCON_USED_OR_UNUSED to mark
`earlycon_acpi_spcr_enable` as maybe_unused.

Fix the following warning (treated as error in W=1)

  CC      arch/powerpc/kernel/setup-common.o
In file included from ./include/linux/serial_8250.h:14:0,
                 from arch/powerpc/kernel/setup-common.c:33:
./include/linux/serial_core.h:382:19: error: ‘earlycon_acpi_spcr_enable’ defined but not used [-Werror=unused-const-variable=]
 static const bool earlycon_acpi_spcr_enable;
                   ^~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15 17:42:55 +01:00
Linus Torvalds 54ce685cae More ACPI updates for v4.16-rc1
- Update the ACPICA kernel code to upstream revision 20180105 including:
    * Assorted fixes (Jung-uk Kim).
    * Support for X32 ABI compilation (Anuj Mittal).
    * Update of ACPICA copyrights to 2018 (Bob Moore).
 
  - Prepare for future modifications to avoid executing the _STA control
    method too early (Hans de Goede).
 
  - Make the processor performance control library code ignore _PPC
    notifications if they cannot be handled and fix up the C1 idle
    state definition when it is used as a fallback state (Chen Yu,
    Yazen Ghannam).
 
  - Make it possible to use the SPCR table on x86 and to replace the
    original IORT table with a new one from initrd (Prarit Bhargava,
    Shunyong Yang).
 
  - Add battery-related quirks for Asus UX360UA and UX410UAK and add
    quirks for table parsing on Dell XPS 9570 and Precision M5530
    (Kai Heng Feng).
 
  - Address static checker warnings in the CPPC code (Gustavo Silva).
 
  - Avoid printing a raw pointer to the kernel log in the smart
    battery driver (Greg Kroah-Hartman).
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJafGvJAAoJEILEb/54YlRxiusQAKUa+OM/oxTJkOEfGGRM8NlS
 Hq/PaL/TnAj3nCoZN9fM38mI4gkxqu3eVMv6kfiqRe8VYmUX9r9tRbQ9kxvEYa7n
 s6Dl+wdC9UND20QJkYVzPlaXbPuZyLFHt4Fkb1hp+HAGgNNYqc4e0lJvI82F2pdo
 im1UFI84jg9UQV4WpUJL6ny2c/RMNtpUV5fOKFD8lkvBvVe7mtZTZ+1nZDeqXGkV
 jzdrVTHLUEDhjS1o0TBmEsJGNeGOqnK/f+m8Rq4397guPAQQq18MYNC68SzhuGjP
 iqhvIvI9sF197i66l/qgsubBifOV4At8Wb0LA5cU8CQLLpEW8GDktz/kucVHyzJ4
 cVKuPXptBwwtPbNFHWO8reTUFMAnP7IpjtC31ntr6xWRQCiXv0/i2hRRN54g9T7e
 FAOBmmys5DKFOq50OB5WdD3/Qz5OUuVgdbrSxNFARIZpQFtUn7Np2/nmNpPgrrcl
 77hO8dpeXUTVvM4HpRQN1+r0KOTLfTAvWV7LYLAjCF9ivc0Vop/tYZQ2VEMSUEFD
 SGKC30mGC4pphAjxcSYV282JR7Jx7arQ71ZA5uYTRRuxnEQd/2MC71fNjrFmCgUW
 1Pumw0Pw6eZRjj1FZ/pj0X5lm7AlZj0dVzsJFgNb0FcJW0nOhN3czQrA4igoSVng
 B2sRv9U8YDnDtzHyTPrY
 =rVdp
 -----END PGP SIGNATURE-----

Merge tag 'acpi-part2-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups, a few new quirks, a couple of
  updates related to the handling of ACPI tables and ACPICA copyrights
  refreshment.

  Specifics:

   - Update the ACPICA kernel code to upstream revision 20180105
     including:
       * Assorted fixes (Jung-uk Kim)
       * Support for X32 ABI compilation (Anuj Mittal)
       * Update of ACPICA copyrights to 2018 (Bob Moore)

   - Prepare for future modifications to avoid executing the _STA
     control method too early (Hans de Goede)

   - Make the processor performance control library code ignore _PPC
     notifications if they cannot be handled and fix up the C1 idle
     state definition when it is used as a fallback state (Chen Yu,
     Yazen Ghannam)

   - Make it possible to use the SPCR table on x86 and to replace the
     original IORT table with a new one from initrd (Prarit Bhargava,
     Shunyong Yang)

   - Add battery-related quirks for Asus UX360UA and UX410UAK and add
     quirks for table parsing on Dell XPS 9570 and Precision M5530 (Kai
     Heng Feng)

   - Address static checker warnings in the CPPC code (Gustavo Silva)

   - Avoid printing a raw pointer to the kernel log in the smart battery
     driver (Greg Kroah-Hartman)"

* tag 'acpi-part2-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: sbshc: remove raw pointer from printk() message
  ACPI: SPCR: Make SPCR available to x86
  ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit
  ACPI / tables: Add IORT to injectable table list
  ACPI / bus: Parse tables as term_list for Dell XPS 9570 and Precision M5530
  ACPICA: Update version to 20180105
  ACPICA: All acpica: Update copyrights to 2018
  ACPI / processor: Set default C1 idle state description
  ACPI / battery: Add quirk for Asus UX360UA and UX410UAK
  ACPI: processor_perflib: Do not send _PPC change notification if not ready
  ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs
  ACPI / bus: Do not call _STA on battery devices with unmet dependencies
  PCI: acpiphp_ibm: prepare for acpi_get_object_info() no longer returning status
  ACPI: export acpi_bus_get_status_handle()
  ACPICA: Add a missing pair of parentheses
  ACPICA: Prefer ACPI_TO_POINTER() over ACPI_ADD_PTR()
  ACPICA: Avoid NULL pointer arithmetic
  ACPICA: Linux: add support for X32 ABI compilation
  ACPI / video: Use true for boolean value
2018-02-09 09:44:25 -08:00
Prarit Bhargava 0231d00082 ACPI: SPCR: Make SPCR available to x86
SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup
an early console.

General fixes include updating Documentation & Kconfig (for x86),
updating comments, and changing parse_spcr() to acpi_parse_spcr(),
and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be
more descriptive.

On x86, many systems have a valid SPCR table but the table version is
not 2 so the table version check must be a warning.

On ARM64 when the kernel parameter earlycon is used both the early console
and console are enabled.  On x86, only the earlycon should be enabled by
by default.  Modify acpi_parse_spcr() to allow options for initializing
the early console and console separately.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-07 11:39:58 +01:00
Paul Cercueil 0f646b63a1 serial: core: Make uart_parse_options take const char* argument
The pointed string is never modified from within uart_parse_options, so
it should be marked as const in the function prototype.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 16:46:26 +01:00
Lukas Wunner 743f93f822 serial: Make retrieval of rs485 properties platform-agnostic
Commit ef838a81dd ("serial: Add common rs485 device tree parsing
function") consolidated retrieval of rs485 OF properties in a common
helper function but did not #ifdef it to CONFIG_OF.  The function is
therefore included on ACPI platforms as well even though it's not used.

On the other hand ACPI platforms with rs485 do exist (e.g. Siemens
IOT2040) and they may leverage _DSD to store rs485 properties.  Likewise,
UART platform devices instantiated from an MFD should be able to specify
rs485 properties.  In fact, the tty subsystem maintainer had asked for
a "generic" function during review of commit ef838a81dd4d:
https://marc.info/?l=linux-serial&m=150143441725194&w=4

Thus, instead of constraining the helper to OF platforms, make it
platform-agnostic by converting it to device_property_*() functions
and renaming it accordingly.

In imx.c, move the invocation of uart_get_rs485_mode() from
serial_imx_probe_dt() to serial_imx_probe() so that it also gets called
for non-OF devices.

In omap-serial.c, move its invocation further up within
serial_omap_probe_rs485() so that the RTS polarity can be overridden
with the driver-specific "rs485-rts-active-high" property once we
introduce a generic "rs485-rts-active-low" property.

Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28 16:04:57 +01:00
Uwe Kleine-König ef838a81dd serial: Add common rs485 device tree parsing function
Several drivers have the same device tree parsing code. Create
a common helper function for it.

This patch bases on work done by Sascha Hauer.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-18 18:36:25 +02:00
Andy Shevchenko aef3ad103a serial: core: remove unneeded irq_wake flag
There is no need to duplicate a flag which IRQ core takes care of.

Replace custom flag by IRQ core API that retrieves its state.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 20:51:20 +02:00
Andy Shevchenko c7ac15ce89 serial: core: move UPF_NO_TXEN_TEST to quirks and rename
First 16 bits in the flags field are user-visible except
UPF_NO_TXEN_TEST. To keep it clean we introduce internal quirks and move
UPF_NO_TXEN_TEST to them. Rename the constant to UPQ_NO_TXEN_TEST to
distinguish with port flags. Users are converted accordingly.

The quirks field might be extended later to hold the additional ones.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30 07:44:22 -07:00
Joel Stanley ea5244e2af serial: 8250: Add flag so drivers can avoid THRE probe
The probing of THRE irq behaviour assumes the other end will be reading
bytes out of the buffer in order to probe the port at driver init. In
some cases the other end cannot be relied upon to read these bytes, so
provide a flag for them to skip this step.

Bit 19 was chosen as the flags are a int and the top bits are taken.

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Andy Shevchenko 2e94d5ae5d serial: core: constify struct uart_port {name} field
Don't allow modifications of port name. It's serial core's business only.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:51:57 +02:00
Vignesh R f7048b1590 tty: serial_core: Add name field to uart_port struct
Introduce a field to store name of uart_port that can be used to easily
identify UART port instances on a system that has more than one UART
instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N
is number that particular UART instance.
This field will be useful when printing debug info for a particular port
or in register IRQs with unique IRQ name. Port name is populated during
uart_add_one_port().

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Felix Fietkau 732dbf3a61 serial: do not accept sysrq characters via serial port
many embedded boards have a disconnected TTL level serial which can
generate some garbage that can lead to spurious false sysrq detects.

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12 11:51:24 +01:00
Michael S. Tsirkin 9efeccacd3 linux: drop __bitwise__ everywhere
__bitwise__ used to mean "yes, please enable sparse checks
unconditionally", but now that we dropped __CHECK_ENDIAN__
__bitwise is exactly the same.
There aren't many users, replace it by __bitwise everywhere.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Akced-by: Lee Duncan <lduncan@suse.com>
2016-12-16 00:13:41 +02:00
Ed Blake db405a8f8b serial: 8250: Expose set_ldisc function
Expose set_ldisc() function so that it can be overridden with a
platform specific implementation.

Signed-off-by: Ed Blake <ed.blake@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:59:38 +01:00