Re: [PATCH] drm: rcar-du: fix reference leak in rcar_cmm_enable

From: Laurent Pinchart
Date: Tue Dec 15 2020 - 13:52:58 EST


Hi Qinglang,

Thank you for the patch.

On Fri, Nov 27, 2020 at 05:44:44PM +0800, Qinglang Miao wrote:
> pm_runtime_get_sync will increment pm usage counter even it
> failed. Forgetting to putting operation will result in a
> reference leak here.
>
> A new function pm_runtime_resume_and_get is introduced in
> [0] to keep usage counter balanced. So We fix the reference
> leak by replacing it with new funtion.
>
> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
>
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

And queued for v5.11.

> ---
> drivers/gpu/drm/rcar-du/rcar_cmm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> index c578095b0..382d53f8a 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_cmm.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> @@ -122,7 +122,7 @@ int rcar_cmm_enable(struct platform_device *pdev)
> {
> int ret;
>
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> if (ret < 0)
> return ret;
>

--
Regards,

Laurent Pinchart