[PATCH] media: st-delta: Fix PM disable depth imbalance in delta_probe

[PATCH] media: st-delta: Fix PM disable depth imbalance in delta_probe

[Miaoqian Lin]

The pm_runtime_enable will increase power disable depth.
If the probe fails, we should use pm_runtime_disable() to balance
pm_runtime_enable().

Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/media/platform/sti/delta/delta-v4l2.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
index c887a31ebb54..dbcfd0484da4 100644
--- a/drivers/media/platform/sti/delta/delta-v4l2.c
+++ b/drivers/media/platform/sti/delta/delta-v4l2.c
@@ -1898,6 +1898,8 @@ static int delta_probe(struct platform_device *pdev)
 	destroy_workqueue(delta->work_queue);
 err_v4l2:
 	v4l2_device_unregister(&delta->v4l2_dev);
+disable_pm_runtime:
+	pm_runtime_disable(dev);
 err:
 	return ret;
 }
-- 
2.17.1

[PATCH v2] media: st-delta: Fix PM disable depth imbalance in delta_probe

[Miaoqian Lin]

The pm_runtime_enable will increase power disable depth.
If the probe fails, we should use pm_runtime_disable() to balance
pm_runtime_enable().

Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
changes in v2:
- remove unused label.
---
 drivers/media/platform/sti/delta/delta-v4l2.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
index c887a31ebb54..36ce0775f3f9 100644
--- a/drivers/media/platform/sti/delta/delta-v4l2.c
+++ b/drivers/media/platform/sti/delta/delta-v4l2.c
@@ -1899,6 +1899,7 @@ static int delta_probe(struct platform_device *pdev)
 err_v4l2:
 	v4l2_device_unregister(&delta->v4l2_dev);
 err:
+	pm_runtime_disable(dev);
 	return ret;
 }
 
-- 
2.17.1

Re: [PATCH v2] media: st-delta: Fix PM disable depth imbalance in delta_probe

[Hans Verkuil]

Hi Miaoqian Lin,

On 3/1/22 04:12, Miaoqian Lin wrote:
> The pm_runtime_enable will increase power disable depth.
> If the probe fails, we should use pm_runtime_disable() to balance
> pm_runtime_enable().
> 
> Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> changes in v2:
> - remove unused label.
> ---
>  drivers/media/platform/sti/delta/delta-v4l2.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
> index c887a31ebb54..36ce0775f3f9 100644
> --- a/drivers/media/platform/sti/delta/delta-v4l2.c
> +++ b/drivers/media/platform/sti/delta/delta-v4l2.c
> @@ -1899,6 +1899,7 @@ static int delta_probe(struct platform_device *pdev)
>  err_v4l2:
>  	v4l2_device_unregister(&delta->v4l2_dev);
>  err:
> +	pm_runtime_disable(dev);

This isn't right. If the devm_kzalloc at the beginning fails, then it also jump
to this label, but at that time no pm_runtime_enable() has been called yet,
so this patch will just introduce another imbalance.

You *do* need a new label here (like you did in v1 of this patch), and update
the 'goto err;' instances after the call to pm_runtime_enable() to go to that
new label.

Regards,

	Hans

>  	return ret;
>  }
>  

[PATCH v3] media: st-delta: Fix PM disable depth imbalance in delta_probe

[Miaoqian Lin]

The pm_runtime_enable will decrease power disable depth.
If the probe fails, we should use pm_runtime_disable() to balance
pm_runtime_enable().

Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
changes in v2:
- remove unused label.
changes in v3:
- add err_pm_disable label and update related 'goto err'.
- update commit message
---
 drivers/media/platform/sti/delta/delta-v4l2.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
index c887a31ebb54..420ad4d8df5d 100644
--- a/drivers/media/platform/sti/delta/delta-v4l2.c
+++ b/drivers/media/platform/sti/delta/delta-v4l2.c
@@ -1859,7 +1859,7 @@ static int delta_probe(struct platform_device *pdev)
 	if (ret) {
 		dev_err(delta->dev, "%s failed to initialize firmware ipc channel\n",
 			DELTA_PREFIX);
-		goto err;
+		goto err_pm_disable;
 	}
 
 	/* register all available decoders */
@@ -1873,7 +1873,7 @@ static int delta_probe(struct platform_device *pdev)
 	if (ret) {
 		dev_err(delta->dev, "%s failed to register V4L2 device\n",
 			DELTA_PREFIX);
-		goto err;
+		goto err_pm_disable;
 	}
 
 	delta->work_queue = create_workqueue(DELTA_NAME);
@@ -1898,6 +1898,8 @@ static int delta_probe(struct platform_device *pdev)
 	destroy_workqueue(delta->work_queue);
 err_v4l2:
 	v4l2_device_unregister(&delta->v4l2_dev);
+err_pm_disable:
+	pm_runtime_disable(dev);
 err:
 	return ret;
 }
-- 
2.17.1

Re: [PATCH v3] media: st-delta: Fix PM disable depth imbalance in delta_probe

[Hugues FRUCHET - FOSS]

Hi Miaoqian Lin,

Thanks for the patch !

Acked-by: Hugues Fruchet <hugues.fruchet@foss.st.com>

BR,
Hugues.

On 3/7/22 9:08 AM, Miaoqian Lin wrote:
> The pm_runtime_enable will decrease power disable depth.
> If the probe fails, we should use pm_runtime_disable() to balance
> pm_runtime_enable().
> 
> Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> changes in v2:
> - remove unused label.
> changes in v3:
> - add err_pm_disable label and update related 'goto err'.
> - update commit message
> ---
>   drivers/media/platform/sti/delta/delta-v4l2.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
> index c887a31ebb54..420ad4d8df5d 100644
> --- a/drivers/media/platform/sti/delta/delta-v4l2.c
> +++ b/drivers/media/platform/sti/delta/delta-v4l2.c
> @@ -1859,7 +1859,7 @@ static int delta_probe(struct platform_device *pdev)
>   	if (ret) {
>   		dev_err(delta->dev, "%s failed to initialize firmware ipc channel\n",
>   			DELTA_PREFIX);
> -		goto err;
> +		goto err_pm_disable;
>   	}
>   
>   	/* register all available decoders */
> @@ -1873,7 +1873,7 @@ static int delta_probe(struct platform_device *pdev)
>   	if (ret) {
>   		dev_err(delta->dev, "%s failed to register V4L2 device\n",
>   			DELTA_PREFIX);
> -		goto err;
> +		goto err_pm_disable;
>   	}
>   
>   	delta->work_queue = create_workqueue(DELTA_NAME);
> @@ -1898,6 +1898,8 @@ static int delta_probe(struct platform_device *pdev)
>   	destroy_workqueue(delta->work_queue);
>   err_v4l2:
>   	v4l2_device_unregister(&delta->v4l2_dev);
> +err_pm_disable:
> +	pm_runtime_disable(dev);
>   err:
>   	return ret;
>   }
>