Re: [PATCH 0/5] gpio: cdev: bail out of poll() if the device goes down

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Wed, Aug 16, 2023 at 2:20 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> Wake up all three wake queues (the one associated with the character
> device file, the one for V1 line events and the V2 line request one)
> when the underlying GPIO device is unregistered. This way we won't get
> stuck in poll() after the chip is gone as user-space will be forced to
> go back into a new system call and will see that gdev->chip is NULL.
>
> Bartosz Golaszewski (5):
>   gpio: cdev: ignore notifications other than line status changes
>   gpio: cdev: rename the notifier block and notify callback
>   gpio: cdev: wake up chardev poll() on device unbind
>   gpio: cdev: wake up linereq poll() on device unbind
>   gpio: cdev: wake up lineevent poll() on device unbind

I see why this is needed and while the whole notification chain
is a bit clunky I really cannot think about anything better so:
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij