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Tony Lindgren a522f1d0c3 gpio: omap: Fix lost edge wake-up interrupts
If an edge interrupt triggers while entering idle just before we save
GPIO datain register to saved_datain, the triggered GPIO will not be
noticed on wake-up. This is because the saved_datain and GPIO datain
are the same on wake-up in omap_gpio_unidle(). Let's fix this by
ignoring any pending edge interrupts for saved_datain.

This issue affects only idle states where the GPIO module internal
wake-up path is operational. For deeper idle states where the GPIO
module gets powered off, Linux generic wakeirqs must be used for
the padconf wake-up events with pinctrl-single driver. For examples,
please see "interrupts-extended" dts usage in many drivers.

This issue can be somewhat easily reproduced by pinging an idle system
with smsc911x Ethernet interface configured IRQ_TYPE_EDGE_FALLING. At
some point the smsc911x interrupts will just stop triggering. Also if
WLCORE WLAN is used with EDGE interrupt like it's documentation specifies,
we can see lost interrupts without this patch.

Note that in the long run we may be able to cancel entering idle by
returning an error in gpio_omap_cpu_notifier() on pending interrupts.
But let's fix the bug first.

Also note that because of the recent clean-up efforts this patch does
not apply directly to older kernels. This does fix a long term issue
though, and can be backported as needed.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-06-12 14:32:04 +02:00
Documentation fmc: Delete the FMC subsystem 2019-06-12 14:23:50 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch gpio: pass lookup and descriptor flags to request_own 2019-06-07 23:20:23 +02:00
block blk-mq: fix hang caused by freeze/unfreeze sequence 2019-05-23 10:25:26 -06:00
certs treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102 2019-05-24 17:39:00 +02:00
drivers gpio: omap: Fix lost edge wake-up interrupts 2019-06-12 14:32:04 +02:00
fs Bug fixes (including a regression fix) for ext4. 2019-05-25 15:03:12 -07:00
include fmc: Delete the FMC subsystem 2019-06-12 14:23:50 +02:00
init treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ipc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 52 2019-05-24 17:36:42 +02:00
kernel Make the GCC 9 warning for sub struct memset go away. 2019-05-26 13:49:40 -07:00
lib for-linus-20190524 2019-05-24 16:02:14 -07:00
mm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98 2019-05-24 17:37:54 +02:00
net SPDX update for 5.2-rc2, round 2 2019-05-24 14:31:58 -07:00
samples treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
scripts Devicetree fixes for 5.2: 2019-05-24 15:16:46 -07:00
security SPDX update for 5.2-rc2, round 2 2019-05-24 14:31:58 -07:00
sound treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 119 2019-05-24 17:39:02 +02:00
tools The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: exclude .get_maintainer.ignore and .gitattributes 2019-05-18 11:49:54 +09:00
.mailmap A reasonably busy cycle for docs, including: 2019-05-08 12:42:50 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
Makefile Linux 5.2-rc2 2019-05-26 16:49:19 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.