On Wed, 28 Apr 2021 16:51:33 +0200
Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> wrote:
> Right now, the driver just assumes that PM runtime resume
> worked, but it may fail.
>
> Well, the pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
>
> So, using it is tricky. Let's replace it by the new
> pm_runtime_resume_and_get(), introduced by:
> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> and return an error if something bad happens.
>
> This should ensure that the PM runtime usage_count will be
> properly decremented if an error happens at open time.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/media/platform/renesas-ceu.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c
> index cd137101d41e..17f01b6e3fe0 100644
> --- a/drivers/media/platform/renesas-ceu.c
> +++ b/drivers/media/platform/renesas-ceu.c
> @@ -1099,10 +1099,10 @@ static int ceu_open(struct file *file)
>
> mutex_lock(&ceudev->mlock);
> /* Causes soft-reset and sensor power on on first open */
> - pm_runtime_get_sync(ceudev->dev);
> + ret = pm_runtime_resume_and_get(ceudev->dev);
> mutex_unlock(&ceudev->mlock);
>
> - return 0;
> + return ret;
> }
>
> static int ceu_release(struct file *file)
