[PATCH] media: platform: s3c-camif: Fix runtime PM imbalance in s3c_camif_open

[PATCH] media: platform: s3c-camif: Fix runtime PM imbalance in s3c_camif_open

[Dinghao Liu]

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code. Thus a pairing decrement is needed on
the error handling path to keep the counter balanced.

Also, call pm_runtime_put() and v4l2_fh_release() when sensor_set_power()
returns an error code.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---
 drivers/media/platform/s3c-camif/camif-capture.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
index 9ca49af29542..d42d9cfaf674 100644
--- a/drivers/media/platform/s3c-camif/camif-capture.c
+++ b/drivers/media/platform/s3c-camif/camif-capture.c
@@ -552,11 +552,9 @@ static int s3c_camif_open(struct file *file)
 		goto err_pm;
 
 	ret = sensor_set_power(camif, 1);
-	if (!ret)
-		goto unlock;
 
-	pm_runtime_put(camif->dev);
 err_pm:
+	pm_runtime_put(camif->dev);
 	v4l2_fh_release(file);
 unlock:
 	mutex_unlock(&camif->lock);
-- 
2.17.1

Re: [PATCH] media: platform: s3c-camif: Fix runtime PM imbalance in s3c_camif_open

[Hans Verkuil]

On 22/05/2020 10:29, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code. Thus a pairing decrement is needed on
> the error handling path to keep the counter balanced.
> 
> Also, call pm_runtime_put() and v4l2_fh_release() when sensor_set_power()
> returns an error code.
> 
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>  drivers/media/platform/s3c-camif/camif-capture.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
> index 9ca49af29542..d42d9cfaf674 100644
> --- a/drivers/media/platform/s3c-camif/camif-capture.c
> +++ b/drivers/media/platform/s3c-camif/camif-capture.c
> @@ -552,11 +552,9 @@ static int s3c_camif_open(struct file *file)
>  		goto err_pm;
>  
>  	ret = sensor_set_power(camif, 1);
> -	if (!ret)
> -		goto unlock;

This is wrong, now this will call v4l2_fh_release() as well on success.

This needs to be reworked.

Regards,

	Hans

>  
> -	pm_runtime_put(camif->dev);
>  err_pm:
> +	pm_runtime_put(camif->dev);
>  	v4l2_fh_release(file);
>  unlock:
>  	mutex_unlock(&camif->lock);
>