Re: [PATCH v2] media: hi846: fix usage of pm_runtime_get_if_in_use()

From: Sakari Ailus
Date: Tue May 16 2023 - 09:23:07 EST


Hi Martin,

On Tue, Apr 25, 2023 at 11:47:47AM +0200, Martin Kepplinger wrote:
> pm_runtime_get_if_in_use() does not only return nonzero values when
> the device is in use, it can return a negative errno too.
>
> And especially during resuming from system suspend, when runtime pm
> is not yet up again, -EAGAIN is being returned, so the subsequent
> pm_runtime_put() call results in a refcount underflow.
>
> Fix system-resume by handling -EAGAIN of pm_runtime_get_if_in_use().
>
> Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxx>
> ---
>
> revision history
> ----------------
> v2 (thank you Sakari and Laurent):
> * drop the other patch (the streaming-state in suspend/resume needs to
> be solved differently).
> * Sakari pointed out that many drivers are affected by this and that
> runtime-pm might need changes instead. I think this patch doesn't hurt
> and could serve as a reminder to do so.

I guess it's appropriate to add:

Fixes: e8c0882685f9 ("media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera")

--
Sakari Ailus