Re: [PATCH v4 10/79] media: mdk-mdp: fix pm_runtime_get_sync() usage count

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 28 Apr 2021 16:51:31 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 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 and avoid memory
> leaks.
> 
> While here, fix the return contition of mtk_mdp_m2m_start_streaming(),
> as it doesn't make any sense to return 0 if the PM runtime failed
> to resume.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> index ace4528cdc5e..f14779e7596e 100644
> --- a/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c
> @@ -391,12 +391,12 @@ static int mtk_mdp_m2m_start_streaming(struct vb2_queue *q, unsigned int count)
>  	struct mtk_mdp_ctx *ctx = q->drv_priv;
>  	int ret;
>  
> -	ret = pm_runtime_get_sync(&ctx->mdp_dev->pdev->dev);
> +	ret = pm_runtime_resume_and_get(&ctx->mdp_dev->pdev->dev);
>  	if (ret < 0)
> -		mtk_mdp_dbg(1, "[%d] pm_runtime_get_sync failed:%d",
> +		mtk_mdp_dbg(1, "[%d] pm_runtime_resume_and_get failed:%d",
>  			    ctx->id, ret);
>  
> -	return 0;
> +	return ret;
>  }
>  
>  static void *mtk_mdp_m2m_buf_remove(struct mtk_mdp_ctx *ctx,