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

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

[Qinglang Miao]

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@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 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;
 
-- 
2.23.0

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

[Jacopo Mondi]

Hello Qinglang,

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")

I -think- you can break this line. Anyway, maintainers can fix when
applying if they feel to.

>
> Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>

Seems fair!
Acked-by: Jacopo Mondi <jacopo@jmondi.org>

Thanks
  j

> ---
>  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;
>
> --
> 2.23.0
>

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

[Laurent Pinchart]

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@huawei.com>
> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>

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

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