Re: [PATCH] serial: st-asc: don't get/put GPIOs in atomic context

[Linus Walleij]

On Wed, Feb 14, 2024 at 10:24 AM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> Since commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with
> SRCU") gpiod_set_consumer_name() calls synchronize_srcu() which led to
> a "sleeping in atomic context" smatch warning.
>
> This function (along with gpiod_get/put() and all other GPIO APIs apart
> from gpiod_get/set_value() and gpiod_direction_input/output()) should
> have never been called with a spinlock taken. We're only fixing this now
> as GPIOLIB has been rebuilt to use SRCU for access serialization which
> uncovered this problem.
>
> Move the calls to gpiod_get/put() outside the spinlock critical section.
>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-gpio/deee1438-efc1-47c4-8d80-0ab2cf01d60a@moroto.mountain/
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Good find!
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij