Re: [PATCH RFT] gpio: cdev: use raw notifier

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Tue, Mar 11, 2025 at 2:54 PM David Jander <david@xxxxxxxxxxx> wrote:
>
> On Tue, 11 Mar 2025 14:19:40 +0100
> Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > Atomic notifiers call rcu_synchronize() in
> > atomic_notifier_chain_unregister() causing a considerable delay in some
> > circumstances. Replace the atomic notifier with the raw variant and
> > provide synchronization with a read-write spinlock.
> >
> > Fixes: fcc8b637c542 ("gpiolib: switch the line state notifier to atomic")
> > Reported-by: David Jander <david@xxxxxxxxxxx>
> > Closes: https://lore.kernel.org/all/20250311110034.53959031@erd003.prtnl/
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > ---
>
> Tested-by: David Jander <david@xxxxxxxxxxx>
>
> Thanks!
>
> Seems to work correctly under some basic testing.
>

Thanks for testing, I'll improve the commit message and resend with your tag.

Bart