[PATCH] [v2] media: imx: imx7-mipi-csis: Fix runtime PM imbalance in mipi_csis_s_stream

[PATCH] [v2] media: imx: imx7-mipi-csis: Fix runtime PM imbalance in mipi_csis_s_stream

[Dinghao Liu]

When v4l2_subdev_call() fails, a pairing PM usage counter
decrement is needed to keep the counter balanced. It's the
same for the following error paths in case 'enable' is on.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---

Changelog:

v2: - Use pm_runtime_put() to balance the refcount.
---
 drivers/staging/media/imx/imx7-mipi-csis.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
index a01a7364b4b9..6f3e8a15e7c4 100644
--- a/drivers/staging/media/imx/imx7-mipi-csis.c
+++ b/drivers/staging/media/imx/imx7-mipi-csis.c
@@ -628,7 +628,7 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
 		}
 		ret = v4l2_subdev_call(state->src_sd, core, s_power, 1);
 		if (ret < 0)
-			return ret;
+			goto pm_put;
 	}
 
 	mutex_lock(&state->lock);
@@ -657,7 +657,8 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
 
 unlock:
 	mutex_unlock(&state->lock);
-	if (!enable)
+pm_put:
+	if (!enable || (ret < 0))
 		pm_runtime_put(&state->pdev->dev);
 
 	return ret;
-- 
2.17.1

Re: [PATCH] [v2] media: imx: imx7-mipi-csis: Fix runtime PM imbalance in mipi_csis_s_stream

[Rui Miguel Silva]

Hi Liu,
Many thanks for the patch.

On Fri, Apr 09, 2021 at 04:22:25PM +0800, Dinghao Liu wrote:
> When v4l2_subdev_call() fails, a pairing PM usage counter
> decrement is needed to keep the counter balanced. It's the
> same for the following error paths in case 'enable' is on.
> 
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>

LGTM
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>

------
Cheers,
     Rui
> ---
> 
> Changelog:
> 
> v2: - Use pm_runtime_put() to balance the refcount.
> ---
>  drivers/staging/media/imx/imx7-mipi-csis.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
> index a01a7364b4b9..6f3e8a15e7c4 100644
> --- a/drivers/staging/media/imx/imx7-mipi-csis.c
> +++ b/drivers/staging/media/imx/imx7-mipi-csis.c
> @@ -628,7 +628,7 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
>  		}
>  		ret = v4l2_subdev_call(state->src_sd, core, s_power, 1);
>  		if (ret < 0)
> -			return ret;
> +			goto pm_put;
>  	}
>  
>  	mutex_lock(&state->lock);
> @@ -657,7 +657,8 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
>  
>  unlock:
>  	mutex_unlock(&state->lock);
> -	if (!enable)
> +pm_put:
> +	if (!enable || (ret < 0))
>  		pm_runtime_put(&state->pdev->dev);
>  
>  	return ret;
> -- 
> 2.17.1
> 
>