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[PATCH] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe

Miaoqian Lin posted 1 patch 4 years, 5 months ago 
drivers/gpu/drm/v3d/v3d_drv.c | 2 ++
1 file changed, 2 insertions(+)
[PATCH] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Miaoqian Lin 4 years, 5 months ago 
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: 57692c9 ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/gpu/drm/v3d/v3d_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
index bd46396a1ae0..4f293aa733b8 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.c
+++ b/drivers/gpu/drm/v3d/v3d_drv.c
@@ -300,6 +300,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 	v3d_gem_destroy(drm);
 dma_free:
 	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
+pm_disable:
+	pm_runtime_disable(dev);
 	return ret;
 }
 
-- 
2.17.1
Re: [PATCH] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Dave Stevenson 4 years, 5 months ago 
Thanks for the patch.

On Wed, 5 Jan 2022 at 12:04, Miaoqian Lin <linmq006@gmail.com> 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: 57692c9 ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  drivers/gpu/drm/v3d/v3d_drv.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
> index bd46396a1ae0..4f293aa733b8 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.c
> +++ b/drivers/gpu/drm/v3d/v3d_drv.c
> @@ -300,6 +300,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
>         v3d_gem_destroy(drm);
>  dma_free:
>         dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
> +pm_disable:
> +       pm_runtime_disable(dev);

The dma_alloc_wc is done before the pm_runtime_enable, so the cleanup
should be in the opposite order.
Functionally it makes minimal difference in this case as
pm_runtime_enable can't fail, but could cause confusion/errors should
any other initialisation step be added between the two.

The pm_disable label is also unused so not necessary, however if
reversing the order then renaming dma_free to pm_disable would be
sensible.

  Dave

>         return ret;
>  }

>
> --
> 2.17.1
>
[PATCH v2] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Miaoqian Lin 4 years, 5 months ago 
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: 57692c9 ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
Changes in v2
- put pm_runtime_disable before dma_free_wc
- rename dma_free to pm_disable
---
 drivers/gpu/drm/v3d/v3d_drv.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
index bd46396a1ae0..7d500dd5314e 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.c
+++ b/drivers/gpu/drm/v3d/v3d_drv.c
@@ -282,7 +282,7 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 
 	ret = v3d_gem_init(drm);
 	if (ret)
-		goto dma_free;
+		goto pm_disable;
 
 	ret = v3d_irq_init(v3d);
 	if (ret)
@@ -298,7 +298,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 	v3d_irq_disable(v3d);
 gem_destroy:
 	v3d_gem_destroy(drm);
-dma_free:
+pm_disable:
+	pm_runtime_disable(dev);
 	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
 	return ret;
 }
-- 
2.17.1
Re: [PATCH v2] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Dave Stevenson 4 years, 5 months ago 
On Thu, 6 Jan 2022 at 12:47, Miaoqian Lin <linmq006@gmail.com> 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: 57692c9 ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>

Thanks for the update - that looks good to me.

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
> Changes in v2
> - put pm_runtime_disable before dma_free_wc
> - rename dma_free to pm_disable
> ---
>  drivers/gpu/drm/v3d/v3d_drv.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
> index bd46396a1ae0..7d500dd5314e 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.c
> +++ b/drivers/gpu/drm/v3d/v3d_drv.c
> @@ -282,7 +282,7 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
>
>         ret = v3d_gem_init(drm);
>         if (ret)
> -               goto dma_free;
> +               goto pm_disable;
>
>         ret = v3d_irq_init(v3d);
>         if (ret)
> @@ -298,7 +298,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
>         v3d_irq_disable(v3d);
>  gem_destroy:
>         v3d_gem_destroy(drm);
> -dma_free:
> +pm_disable:
> +       pm_runtime_disable(dev);
>         dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
>         return ret;
>  }
> --
> 2.17.1
>
Re: [PATCH v2] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Melissa Wen 4 years, 5 months ago 
On 01/06, 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: 57692c9 ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> Changes in v2
> - put pm_runtime_disable before dma_free_wc
> - rename dma_free to pm_disable
> ---
>  drivers/gpu/drm/v3d/v3d_drv.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
> index bd46396a1ae0..7d500dd5314e 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.c
> +++ b/drivers/gpu/drm/v3d/v3d_drv.c
> @@ -282,7 +282,7 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
>  
>  	ret = v3d_gem_init(drm);
>  	if (ret)
> -		goto dma_free;
> +		goto pm_disable;
>  
>  	ret = v3d_irq_init(v3d);
>  	if (ret)
> @@ -298,7 +298,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
>  	v3d_irq_disable(v3d);
>  gem_destroy:
>  	v3d_gem_destroy(drm);
> -dma_free:
> +pm_disable:
> +	pm_runtime_disable(dev);

Hi,

I see this pm_runtime_disable balancing is also missing for
v3d_platform_drm_remove(), right?

BR,

Melissa
>  	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
>  	return ret;
>  }
> -- 
> 2.17.1
>
Re: [PATCH v2] drm/v3d: Fix PM disable depth imbalance in v3d_platform_drm_probe
Posted by Miaoqian Lin 4 years, 5 months ago 
Hi Melissa,

On Sun, Jan 09, 2022 at 04:48:17PM -0100, Melissa Wen wrote:
> On 01/06, 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().
> > 
> >  	if (ret)
> > -		goto dma_free;
> > +		goto pm_disable;
> >  
> >  	ret = v3d_irq_init(v3d);
> >  	if (ret)
> > @@ -298,7 +298,8 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
> >  	v3d_irq_disable(v3d);
> >  gem_destroy:
> >  	v3d_gem_destroy(drm);
> > -dma_free:
> > +pm_disable:
> > +	pm_runtime_disable(dev);
> 
> Hi,
> 
> I see this pm_runtime_disable balancing is also missing for
> v3d_platform_drm_remove(), right?
> 
I think, yes. 

> >  	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
> >  	return ret;
> >  }
> > -- 
> > 2.17.1
> >

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