<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/drivers/gpio, branch dev-5.15-intel</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.15-intel</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.15-intel'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2022-04-27T12:39:00+00:00</updated>
<entry>
<title>gpio: Request interrupts after IRQ is initialized</title>
<updated>2022-04-27T12:39:00+00:00</updated>
<author>
<name>Mario Limonciello</name>
<email>mario.limonciello@amd.com</email>
</author>
<published>2022-04-22T13:14:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=571a67b0d8a4d548d550853918746d835eb470f3'/>
<id>urn:sha1:571a67b0d8a4d548d550853918746d835eb470f3</id>
<content type='text'>
commit 06fb4ecfeac7e00d6704fa5ed19299f2fefb3cc9 upstream.

Commit 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members
before initialization") attempted to fix a race condition that lead to a
NULL pointer, but in the process caused a regression for _AEI/_EVT
declared GPIOs.

This manifests in messages showing deferred probing while trying to
allocate IRQs like so:

  amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0000 to IRQ, err -517
  amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x002C to IRQ, err -517
  amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
  [ .. more of the same .. ]

The code for walking _AEI doesn't handle deferred probing and so this
leads to non-functional GPIO interrupts.

Fix this issue by moving the call to `acpi_gpiochip_request_interrupts`
to occur after gc-&gt;irc.initialized is set.

Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
Link: https://lore.kernel.org/linux-gpio/BL1PR12MB51577A77F000A008AA694675E2EF9@BL1PR12MB5157.namprd12.prod.outlook.com/
Link: https://bugzilla.suse.com/show_bug.cgi?id=1198697
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215850
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1979
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1976
Reported-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Shreeya Patel &lt;shreeya.patel@collabora.com&gt;
Tested-By: Samuel Čavoj &lt;samuel@cavoj.net&gt;
Tested-By: lukeluk498@gmail.com Link:
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Acked-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-and-tested-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Cc: Shreeya Patel &lt;shreeya.patel@collabora.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>gpiolib: acpi: use correct format characters</title>
<updated>2022-04-20T07:34:10+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-19T23:21:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d40cf3492277d203c1f676cb9df88ab55d0c5d0f'/>
<id>urn:sha1:d40cf3492277d203c1f676cb9df88ab55d0c5d0f</id>
<content type='text'>
[ Upstream commit 213d266ebfb1621aab79cfe63388facc520a1381 ]

When compiling with -Wformat, clang emits the following warning:

  gpiolib-acpi.c:393:4: warning: format specifies type 'unsigned char' but the argument has type 'int' [-Wformat]
                        pin);
                        ^~~

So warning that '%hhX' is paired with an 'int' is all just completely
mindless and wrong. Sadly, I can see a different bogus warning reason
why people would want to use '%02hhX'.

Again, the *sane* thing from a human perspective is to use '%02X. But
if the compiler doesn't do any range analysis at all, it could decide
that "Oh, that print format could need up to 8 bytes of space in the
result". Using '%02hhX' would cut that down to two.

And since we use

        char ev_name[5];

and currently use "_%c%02hhX" as the format string, even a compiler
that doesn't notice that "pin &lt;= 255" test that guards this all will
go "OK, that's at most 4 bytes and the final NUL termination, so it's
fine".

While a compiler - like gcc - that only sees that the original source
of the 'pin' value is a 'unsigned short' array, and then doesn't take
the "pin &lt;= 255" into account, will warn like this:

  gpiolib-acpi.c: In function 'acpi_gpiochip_request_interrupt':
  gpiolib-acpi.c:206:24: warning: '%02X' directive writing between 2 and 4 bytes into a region of size 3 [-Wformat-overflow=]
       sprintf(ev_name, "_%c%02X",
                            ^~~~
  gpiolib-acpi.c:206:20: note: directive argument in the range [0, 65535]

because gcc isn't being very good at that argument range analysis either.

In other words, the original use of 'hhx' was bogus to begin with, and
due to *another* compiler warning being bad, and we had that bad code
being written back in 2016 to work around _that_ compiler warning
(commit e40a3ae1f794: "gpio: acpi: work around false-positive
-Wstring-overflow warning").

Sadly, two different bad compiler warnings together does not make for
one good one.

It just makes for even more pain.

End result: I think the simplest and cleanest option is simply the
proposed change which undoes that '%hhX' change for gcc, and replaces
it with just using a slightly bigger stack allocation. It's not like
a 5-byte allocation is in any way likely to have saved any actual stack,
since all the other variables in that function are 'int' or bigger.

False-positive compiler warnings really do make people write worse
code, and that's a problem. But on a scale of bad code, I feel that
extending the buffer trivially is better than adding a pointless cast
that literally makes no sense.

At least in this case the end result isn't unreadable or buggy. We've
had several cases of bad compiler warnings that caused changes that
were actually horrendously wrong.

Fixes: e40a3ae1f794 ("gpio: acpi: work around false-positive -Wstring-overflow warning")
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpio: Restrict usage of GPIO chip irq members before initialization</title>
<updated>2022-04-13T18:59:23+00:00</updated>
<author>
<name>Shreeya Patel</name>
<email>shreeya.patel@collabora.com</email>
</author>
<published>2022-03-21T13:32:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=0912cf021fb5749372b3782611d8b1de4986c13a'/>
<id>urn:sha1:0912cf021fb5749372b3782611d8b1de4986c13a</id>
<content type='text'>
commit 5467801f1fcbdc46bc7298a84dbf3ca1ff2a7320 upstream.

GPIO chip irq members are exposed before they could be completely
initialized and this leads to race conditions.

One such issue was observed for the gc-&gt;irq.domain variable which
was accessed through the I2C interface in gpiochip_to_irq() before
it could be initialized by gpiochip_add_irqchip(). This resulted in
Kernel NULL pointer dereference.

Following are the logs for reference :-

kernel: Call Trace:
kernel:  gpiod_to_irq+0x53/0x70
kernel:  acpi_dev_gpio_irq_get_by+0x113/0x1f0
kernel:  i2c_acpi_get_irq+0xc0/0xd0
kernel:  i2c_device_probe+0x28a/0x2a0
kernel:  really_probe+0xf2/0x460
kernel: RIP: 0010:gpiochip_to_irq+0x47/0xc0

To avoid such scenarios, restrict usage of GPIO chip irq members before
they are completely initialized.

Signed-off-by: Shreeya Patel &lt;shreeya.patel@collabora.com&gt;
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Revert "gpio: Revert regression in sysfs-gpio (gpiolib.c)"</title>
<updated>2022-04-08T12:22:47+00:00</updated>
<author>
<name>Bartosz Golaszewski</name>
<email>brgl@bgdev.pl</email>
</author>
<published>2022-03-15T16:52:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=20f46b12162cd19ad0c9e85ea6d817028e364853'/>
<id>urn:sha1:20f46b12162cd19ad0c9e85ea6d817028e364853</id>
<content type='text'>
[ Upstream commit 56e337f2cf1326323844927a04e9dbce9a244835 ]

This reverts commit fc328a7d1fcce263db0b046917a66f3aa6e68719.

This commit - while attempting to fix a regression - has caused a number
of other problems. As the fallout from it is more significant than the
initial problem itself, revert it for now before we find a correct
solution.

Link: https://lore.kernel.org/all/20220314192522.GA3031157@roeck-us.net/
Link: https://lore.kernel.org/stable/20220314155509.552218-1-michael@walle.cc/
Link: https://lore.kernel.org/all/20211217153555.9413-1-marcelo.jimenez@gmail.com/
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Reported-and-bisected-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Reported-by: Michael Walle &lt;michael@walle.cc&gt;
Cc: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Cc: Marcelo Roberto Jimenez &lt;marcelo.jimenez@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpio: Revert regression in sysfs-gpio (gpiolib.c)</title>
<updated>2022-04-08T12:22:47+00:00</updated>
<author>
<name>Marcelo Roberto Jimenez</name>
<email>marcelo.jimenez@gmail.com</email>
</author>
<published>2022-03-07T09:57:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a28571fcc422342c72d531ac4cc0991af98eb8eb'/>
<id>urn:sha1:a28571fcc422342c72d531ac4cc0991af98eb8eb</id>
<content type='text'>
[ Upstream commit fc328a7d1fcce263db0b046917a66f3aa6e68719 ]

Some GPIO lines have stopped working after the patch
commit 2ab73c6d8323f ("gpio: Support GPIO controllers without pin-ranges")

And this has supposedly been fixed in the following patches
commit 89ad556b7f96a ("gpio: Avoid using pin ranges with !PINCTRL")
commit 6dbbf84603961 ("gpiolib: Don't free if pin ranges are not defined")

But an erratic behavior where some GPIO lines work while others do not work
has been introduced.

This patch reverts those changes so that the sysfs-gpio interface works
properly again.

Signed-off-by: Marcelo Roberto Jimenez &lt;marcelo.jimenez@gmail.com&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpio: Return EPROBE_DEFER if gc-&gt;to_irq is NULL</title>
<updated>2022-03-16T13:23:41+00:00</updated>
<author>
<name>Shreeya Patel</name>
<email>shreeya.patel@collabora.com</email>
</author>
<published>2022-02-16T20:26:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=5cf4dd01efe0a7318704dec40c435a54942faf31'/>
<id>urn:sha1:5cf4dd01efe0a7318704dec40c435a54942faf31</id>
<content type='text'>
[ Upstream commit ae42f9288846353982e2eab181fb41e7fd8bf60f ]

We are racing the registering of .to_irq when probing the
i2c driver. This results in random failure of touchscreen
devices.

Following explains the race condition better.

[gpio driver] gpio driver registers gpio chip
[gpio consumer] gpio is acquired
[gpio consumer] gpiod_to_irq() fails with -ENXIO
[gpio driver] gpio driver registers irqchip
gpiod_to_irq works at this point, but -ENXIO is fatal

We could see the following errors in dmesg logs when gc-&gt;to_irq is NULL

[2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ
[2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22

To avoid this situation, defer probing until to_irq is registered.
Returning -EPROBE_DEFER would be the first step towards avoiding
the failure of devices due to the race in registration of .to_irq.
Final solution to this issue would be to avoid using gc irq members
until they are fully initialized.

This issue has been reported many times in past and people have been
using workarounds like changing the pinctrl_amd to built-in instead
of loading it as a module or by adding a softdep for pinctrl_amd into
the config file.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Shreeya Patel &lt;shreeya.patel@collabora.com&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpio: ts4900: Do not set DAT and OE together</title>
<updated>2022-03-16T13:23:39+00:00</updated>
<author>
<name>Mark Featherston</name>
<email>mark@embeddedTS.com</email>
</author>
<published>2022-03-10T01:16:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c7f6accc67950b97059e95af7616df367a129195'/>
<id>urn:sha1:c7f6accc67950b97059e95af7616df367a129195</id>
<content type='text'>
[ Upstream commit 03fe003547975680fdb9ff5ab0e41cb68276c4f2 ]

This works around an issue with the hardware where both OE and
DAT are exposed in the same register. If both are updated
simultaneously, the harware makes no guarantees that OE or DAT
will actually change in any given order and may result in a
glitch of a few ns on a GPIO pin when changing direction and value
in a single write.

Setting direction to input now only affects OE bit. Setting
direction to output updates DAT first, then OE.

Fixes: 9c6686322d74 ("gpio: add Technologic I2C-FPGA gpio support")
Signed-off-by: Mark Featherston &lt;mark@embeddedTS.com&gt;
Signed-off-by: Kris Bahnsen &lt;kris@embeddedTS.com&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpiolib: acpi: Convert ACPI value of debounce to microseconds</title>
<updated>2022-03-16T13:23:37+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2022-03-07T11:56:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c5883d38a470a3fdf25733c5f05a3f9f4c4445ce'/>
<id>urn:sha1:c5883d38a470a3fdf25733c5f05a3f9f4c4445ce</id>
<content type='text'>
[ Upstream commit 660c619b9d7ccd28648ee3766cdbe94ec7b27402 ]

It appears that GPIO ACPI library uses ACPI debounce values directly.
However, the GPIO library APIs expect the debounce timeout to be in
microseconds.

Convert ACPI value of debounce to microseconds.

While at it, document this detail where it is appropriate.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215664
Reported-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Fixes: 8dcb7a15a585 ("gpiolib: acpi: Take into account debounce settings")
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>gpio: tegra186: Fix chip_data type confusion</title>
<updated>2022-03-02T10:48:10+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2022-02-11T09:39:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=83f331d1debb143f9d755b727009bc65028a382f'/>
<id>urn:sha1:83f331d1debb143f9d755b727009bc65028a382f</id>
<content type='text'>
commit d1e972ace42390de739cde87d96043dcbe502286 upstream.

The tegra186 GPIO driver makes the assumption that the pointer
returned by irq_data_get_irq_chip_data() is a pointer to a
tegra_gpio structure. Unfortunately, it is actually a pointer
to the inner gpio_chip structure, as mandated by the gpiolib
infrastructure. Nice try.

The saving grace is that the gpio_chip is the first member of
tegra_gpio, so the bug has gone undetected since... forever.

Fix it by performing a container_of() on the pointer. This results
in no additional code, and makes it possible to understand how
the whole thing works.

Fixes: 5b2b135a87fc ("gpio: Add Tegra186 support")
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Cc: Bartosz Golaszewski &lt;bgolaszewski@baylibre.com&gt;
Link: https://lore.kernel.org/r/20220211093904.1112679-1-maz@kernel.org
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>gpio: rockchip: Reset int_bothedge when changing trigger</title>
<updated>2022-03-02T10:48:01+00:00</updated>
<author>
<name>Samuel Holland</name>
<email>samuel@sholland.org</email>
</author>
<published>2022-02-12T20:50:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=43221f446c0237e6823bbb043b680b004bd24cb6'/>
<id>urn:sha1:43221f446c0237e6823bbb043b680b004bd24cb6</id>
<content type='text'>
[ Upstream commit 7920af5c826cb4a7ada1ae26fdd317642805adc2 ]

With v2 hardware, an IRQ can be configured to trigger on both edges via
a bit in the int_bothedge register. Currently, the driver sets this bit
when changing the trigger type to IRQ_TYPE_EDGE_BOTH, but fails to reset
this bit if the trigger type is later changed to something else. This
causes spurious IRQs, and when using gpio-keys with wakeup-event-action
set to EV_ACT_(DE)ASSERTED, those IRQs translate into spurious wakeups.

Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller")
Reported-by: Guillaume Savaton &lt;guillaume@baierouge.fr&gt;
Tested-by: Guillaume Savaton &lt;guillaume@baierouge.fr&gt;
Signed-off-by: Samuel Holland &lt;samuel@sholland.org&gt;
Signed-off-by: Bartosz Golaszewski &lt;brgl@bgdev.pl&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
