[16/25] media: am437x: fix pm_runtime_get_sync() usage count
diff mbox series

Message ID 8688555079cf30f5848bb020b5ecf0b0132b2c7e.1620207353.git.mchehab+huawei@kernel.org
State New, archived
Headers show
Series
  • Fix some PM runtime issues at the media subsystem
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Commit Message

Mauro Carvalho Chehab May 5, 2021, 9:42 a.m. UTC
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, avoiding
a potential PM usage counter leak.

While here, ensure that the driver will check if PM runtime
resumed at vpfe_initialize_device().

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/platform/am437x/am437x-vpfe.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

Comments

Jonathan Cameron May 5, 2021, 12:32 p.m. UTC | #1
On Wed, 5 May 2021 11:42:06 +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, avoiding
> a potential PM usage counter leak.
> 
> While here, ensure that the driver will check if PM runtime
> resumed at vpfe_initialize_device().
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/media/platform/am437x/am437x-vpfe.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
> index 6cdc77dda0e4..1c9cb9e05fdf 100644
> --- a/drivers/media/platform/am437x/am437x-vpfe.c
> +++ b/drivers/media/platform/am437x/am437x-vpfe.c
> @@ -1021,7 +1021,9 @@ static int vpfe_initialize_device(struct vpfe_device *vpfe)
>  	if (ret)
>  		return ret;
>  
> -	pm_runtime_get_sync(vpfe->pdev);
> +	ret = pm_runtime_resume_and_get(vpfe->pdev);
> +	if (ret < 0)
> +		return ret;
>  
>  	vpfe_config_enable(&vpfe->ccdc, 1);
>  
> @@ -2443,7 +2445,11 @@ static int vpfe_probe(struct platform_device *pdev)
>  	pm_runtime_enable(&pdev->dev);
>  
>  	/* for now just enable it here instead of waiting for the open */
> -	pm_runtime_get_sync(&pdev->dev);
> +	ret = pm_runtime_resume_and_get(&pdev->dev);
> +	if (ret < 0) {
> +		vpfe_err(vpfe, "Unable to resume device.\n");
> +		goto probe_out_v4l2_unregister;
> +	}
>  
>  	vpfe_ccdc_config_defaults(ccdc);
>  
> @@ -2530,6 +2536,11 @@ static int vpfe_suspend(struct device *dev)
>  
>  	/* only do full suspend if streaming has started */
>  	if (vb2_start_streaming_called(&vpfe->buffer_queue)) {
> +		/*
> +		 * ignore RPM resume errors here, as it is already too late.
> +		 * A check like that should happen earlier, either at
> +		 * open() or just before start streaming.
> +		 */
>  		pm_runtime_get_sync(dev);
>  		vpfe_config_enable(ccdc, 1);
>
Lad, Prabhakar May 8, 2021, 1:01 p.m. UTC | #2
Hi Mauro,

Thank you for the patch.

On Wed, May 5, 2021 at 10:42 AM 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, avoiding
> a potential PM usage counter leak.
>
> While here, ensure that the driver will check if PM runtime
> resumed at vpfe_initialize_device().
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  drivers/media/platform/am437x/am437x-vpfe.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
Acked-by: Lad Prabhakar <prabhakar.csengg@gmail.com>

Cheers,
Prabhakar


> diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
> index 6cdc77dda0e4..1c9cb9e05fdf 100644
> --- a/drivers/media/platform/am437x/am437x-vpfe.c
> +++ b/drivers/media/platform/am437x/am437x-vpfe.c
> @@ -1021,7 +1021,9 @@ static int vpfe_initialize_device(struct vpfe_device *vpfe)
>         if (ret)
>                 return ret;
>
> -       pm_runtime_get_sync(vpfe->pdev);
> +       ret = pm_runtime_resume_and_get(vpfe->pdev);
> +       if (ret < 0)
> +               return ret;
>
>         vpfe_config_enable(&vpfe->ccdc, 1);
>
> @@ -2443,7 +2445,11 @@ static int vpfe_probe(struct platform_device *pdev)
>         pm_runtime_enable(&pdev->dev);
>
>         /* for now just enable it here instead of waiting for the open */
> -       pm_runtime_get_sync(&pdev->dev);
> +       ret = pm_runtime_resume_and_get(&pdev->dev);
> +       if (ret < 0) {
> +               vpfe_err(vpfe, "Unable to resume device.\n");
> +               goto probe_out_v4l2_unregister;
> +       }
>
>         vpfe_ccdc_config_defaults(ccdc);
>
> @@ -2530,6 +2536,11 @@ static int vpfe_suspend(struct device *dev)
>
>         /* only do full suspend if streaming has started */
>         if (vb2_start_streaming_called(&vpfe->buffer_queue)) {
> +               /*
> +                * ignore RPM resume errors here, as it is already too late.
> +                * A check like that should happen earlier, either at
> +                * open() or just before start streaming.
> +                */
>                 pm_runtime_get_sync(dev);
>                 vpfe_config_enable(ccdc, 1);
>
> --
> 2.30.2
>

Patch
diff mbox series

diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index 6cdc77dda0e4..1c9cb9e05fdf 100644
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -1021,7 +1021,9 @@  static int vpfe_initialize_device(struct vpfe_device *vpfe)
 	if (ret)
 		return ret;
 
-	pm_runtime_get_sync(vpfe->pdev);
+	ret = pm_runtime_resume_and_get(vpfe->pdev);
+	if (ret < 0)
+		return ret;
 
 	vpfe_config_enable(&vpfe->ccdc, 1);
 
@@ -2443,7 +2445,11 @@  static int vpfe_probe(struct platform_device *pdev)
 	pm_runtime_enable(&pdev->dev);
 
 	/* for now just enable it here instead of waiting for the open */
-	pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0) {
+		vpfe_err(vpfe, "Unable to resume device.\n");
+		goto probe_out_v4l2_unregister;
+	}
 
 	vpfe_ccdc_config_defaults(ccdc);
 
@@ -2530,6 +2536,11 @@  static int vpfe_suspend(struct device *dev)
 
 	/* only do full suspend if streaming has started */
 	if (vb2_start_streaming_called(&vpfe->buffer_queue)) {
+		/*
+		 * ignore RPM resume errors here, as it is already too late.
+		 * A check like that should happen earlier, either at
+		 * open() or just before start streaming.
+		 */
 		pm_runtime_get_sync(dev);
 		vpfe_config_enable(ccdc, 1);