Re: [PATCH 24/25] media: exynos-gsc: fix pm_runtime_get_sync() usage count

[Jonathan Cameron]

On Wed, 5 May 2021 11:42:14 +0200
Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> wrote:

> The pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
> 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")
> in order to properly decrement the usage counter, avoiding
> a potential PM usage counter leak.
> 
> As a bonus, as pm_runtime_get_sync() always return 0 on
> success, the logic can be simplified.
> 
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

> ---
>  drivers/media/platform/exynos-gsc/gsc-m2m.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/exynos-gsc/gsc-m2m.c b/drivers/media/platform/exynos-gsc/gsc-m2m.c
> index 27a3c92c73bc..f1cf847d1cc2 100644
> --- a/drivers/media/platform/exynos-gsc/gsc-m2m.c
> +++ b/drivers/media/platform/exynos-gsc/gsc-m2m.c
> @@ -56,10 +56,8 @@ static void __gsc_m2m_job_abort(struct gsc_ctx *ctx)
>  static int gsc_m2m_start_streaming(struct vb2_queue *q, unsigned int count)
>  {
>  	struct gsc_ctx *ctx = q->drv_priv;
> -	int ret;
>  
> -	ret = pm_runtime_get_sync(&ctx->gsc_dev->pdev->dev);
> -	return ret > 0 ? 0 : ret;
> +	return pm_runtime_resume_and_get(&ctx->gsc_dev->pdev->dev);
>  }
>  
>  static void __gsc_m2m_cleanup_queue(struct gsc_ctx *ctx)