Commit graph

4 commits

Author SHA1 Message Date
Boerge Struempfel
c1c06d2ec5 gpiolib: sysfs: Fix error handling on failed export
[ Upstream commit 95dd1e34ff5bbee93a28ff3947eceaf6de811b1a ]

If gpio_set_transitory() fails, we should free the GPIO again. Most
notably, the flag FLAG_REQUESTED has previously been set in
gpiod_request_commit(), and should be reset on failure.

To my knowledge, this does not affect any current users, since the
gpio_set_transitory() mainly returns 0 and -ENOTSUPP, which is converted
to 0. However the gpio_set_transitory() function calles the .set_config()
function of the corresponding GPIO chip and there are some GPIO drivers in
which some (unlikely) branches return other values like -EPROBE_DEFER,
and -EINVAL. In these cases, the above mentioned FLAG_REQUESTED would not
be reset, which results in the pin being blocked until the next reboot.

Fixes: e10f72bf4b3e ("gpio: gpiolib: Generalise state persistence beyond sleep")
Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:11:45 +01:00
Haibo Chen
5e649ccc29 gpio: vf610: set value before the direction to avoid a glitch
commit fc363413ef8ea842ae7a99e3caf5465dafdd3a49 upstream.

We found a glitch when configuring the pad as output high. To avoid this
glitch, move the data value setting before direction config in the
function vf610_gpio_direction_output().

Fixes: 659d8a62311f ("gpio: vf610: add imx7ulp support")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
[Bartosz: tweak the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08 11:26:20 +01:00
Chengfeng Ye
b92ff16804 gpio: timberdale: Fix potential deadlock on &tgpio->lock
[ Upstream commit 9e8bc2dda5a7a8e2babc9975f4b11c9a6196e490 ]

As timbgpio_irq_enable()/timbgpio_irq_disable() callback could be
executed under irq context, it could introduce double locks on
&tgpio->lock if it preempts other execution units requiring
the same locks.

timbgpio_gpio_set()
--> timbgpio_update_bit()
--> spin_lock(&tgpio->lock)
<interrupt>
   --> timbgpio_irq_disable()
   --> spin_lock_irqsave(&tgpio->lock)

This flaw was found by an experimental static analysis tool I am
developing for irq-related deadlock.

To prevent the potential deadlock, the patch uses spin_lock_irqsave()
on &tgpio->lock inside timbgpio_gpio_set() to prevent the possible
deadlock scenario.

Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08 11:26:16 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00