dmaengine: xilinx: zynqmp_dma: fix autosuspend cleanup during teardown

[PATCH] dmaengine: xilinx: zynqmp_dma: fix autosuspend cleanup during teardown

Posted by Guangshuo Li 1 month, 3 weeks ago

zynqmp_dma_probe() calls pm_runtime_use_autosuspend(), but its failure
paths and zynqmp_dma_remove() do not call the matching
pm_runtime_dont_use_autosuspend().

If the autosuspend delay is set to a negative value while autosuspend
is enabled, the runtime PM core increments usage_count to prevent
runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
during teardown, this reference is not dropped and usage_count remains
unbalanced.

The documentation for pm_runtime_use_autosuspend() also notes that it
is important to undo it with pm_runtime_dont_use_autosuspend() at
driver exit time, unless runtime PM was initially enabled with
devm_pm_runtime_enable().

Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
failure and remove paths.

This issue was found by manual code inspection.

Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/dma/xilinx/zynqmp_dma.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index f6a812e49ddc..635c3f6cc5c2 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -1116,8 +1116,10 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
 	}
 	if (!pm_runtime_enabled(zdev->dev)) {
 		ret = zynqmp_dma_runtime_resume(zdev->dev);
-		if (ret)
+		if (ret) {
+			pm_runtime_dont_use_autosuspend(zdev->dev);
 			return ret;
+		}
 	}
 
 	ret = zynqmp_dma_chan_probe(zdev, pdev);
@@ -1152,6 +1154,7 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
 err_disable_pm:
 	if (!pm_runtime_enabled(zdev->dev))
 		zynqmp_dma_runtime_suspend(zdev->dev);
+	pm_runtime_dont_use_autosuspend(zdev->dev);
 	pm_runtime_disable(zdev->dev);
 	return ret;
 }
@@ -1172,6 +1175,7 @@ static void zynqmp_dma_remove(struct platform_device *pdev)
 	zynqmp_dma_chan_remove(zdev->chan);
 	if (pm_runtime_active(zdev->dev))
 		zynqmp_dma_runtime_suspend(zdev->dev);
+	pm_runtime_dont_use_autosuspend(zdev->dev);
 	pm_runtime_disable(zdev->dev);
 }
 
-- 
2.43.0

Re: [PATCH] dmaengine: xilinx: zynqmp_dma: fix autosuspend cleanup during teardown

Posted by Krzysztof Kozlowski 1 month, 1 week ago

On 08/08/2026 13:52, Guangshuo Li wrote:
> zynqmp_dma_probe() calls pm_runtime_use_autosuspend(), but its failure
> paths and zynqmp_dma_remove() do not call the matching
> pm_runtime_dont_use_autosuspend().
> 
> If the autosuspend delay is set to a negative value while autosuspend
> is enabled, the runtime PM core increments usage_count to prevent
> runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
> during teardown, this reference is not dropped and usage_count remains
> unbalanced.
> 
> The documentation for pm_runtime_use_autosuspend() also notes that it
> is important to undo it with pm_runtime_dont_use_autosuspend() at
> driver exit time, unless runtime PM was initially enabled with
> devm_pm_runtime_enable().
> 
> Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
> failure and remove paths.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>

You sent vast amount of patches, all separate, making it very difficult
to track and respond in efficient way. Do not do that.

Group your work per subsystem.

You were asked to clarify and respond to incorrect fixes statement. I do
not see how you clarified and responded at all.

Best regards,
Krzysztof

Re: [PATCH] dmaengine: xilinx: zynqmp_dma: fix autosuspend cleanup during teardown

Posted by Guangshuo Li 1 month ago

Hi Krzysztof,

On Thu, 20 Aug 2026 at 22:03, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On 08/08/2026 13:52, Guangshuo Li wrote:
> > zynqmp_dma_probe() calls pm_runtime_use_autosuspend(), but its failure
> > paths and zynqmp_dma_remove() do not call the matching
> > pm_runtime_dont_use_autosuspend().
> >
> > If the autosuspend delay is set to a negative value while autosuspend
> > is enabled, the runtime PM core increments usage_count to prevent
> > runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
> > during teardown, this reference is not dropped and usage_count remains
> > unbalanced.
> >
> > The documentation for pm_runtime_use_autosuspend() also notes that it
> > is important to undo it with pm_runtime_dont_use_autosuspend() at
> > driver exit time, unless runtime PM was initially enabled with
> > devm_pm_runtime_enable().
> >
> > Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
> > failure and remove paths.
> >
> > This issue was found by manual code inspection.
> >
> > Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
>
> You sent vast amount of patches, all separate, making it very difficult
> to track and respond in efficient way. Do not do that.
>
> Group your work per subsystem.
>
> You were asked to clarify and respond to incorrect fixes statement. I do
> not see how you clarified and responded at all.
>
> Best regards,
> Krzysztof

Sorry about that. I should have replied to the earlier review comments
explicitly, and I also should not have sent so many separate patches.

I will group future patches by subsystem and make sure to respond
clearly to review feedback before resending.

Thanks for pointing this out.

Best regards,
Guangshuo

Re: [PATCH] dmaengine: xilinx: zynqmp_dma: fix autosuspend cleanup during teardown

Posted by Frank Li 1 month, 2 weeks ago

On Sat, Aug 08, 2026 at 07:52:28PM +0800, Guangshuo Li wrote:
> zynqmp_dma_probe() calls pm_runtime_use_autosuspend(), but its failure
> paths and zynqmp_dma_remove() do not call the matching
> pm_runtime_dont_use_autosuspend().
>
> If the autosuspend delay is set to a negative value while autosuspend
> is enabled, the runtime PM core increments usage_count to prevent
> runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
> during teardown, this reference is not dropped and usage_count remains
> unbalanced.
>
> The documentation for pm_runtime_use_autosuspend() also notes that it
> is important to undo it with pm_runtime_dont_use_autosuspend() at
> driver exit time, unless runtime PM was initially enabled with
> devm_pm_runtime_enable().
>
> Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
> failure and remove paths.
>
> This issue was found by manual code inspection.
>
> Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/dma/xilinx/zynqmp_dma.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
> index f6a812e49ddc..635c3f6cc5c2 100644
> --- a/drivers/dma/xilinx/zynqmp_dma.c
> +++ b/drivers/dma/xilinx/zynqmp_dma.c
> @@ -1116,8 +1116,10 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
>  	}
>  	if (!pm_runtime_enabled(zdev->dev)) {
>  		ret = zynqmp_dma_runtime_resume(zdev->dev);
> -		if (ret)
> +		if (ret) {
> +			pm_runtime_dont_use_autosuspend(zdev->dev);

Please use devm_runtime_enable() to fix this problem, auto tear down already
include it

static void pm_runtime_disable_action(void *data)
{
	pm_runtime_dont_use_autosuspend(data);
	pm_runtime_disable(data);
}

Frank

>  			return ret;
> +		}
>  	}
>
>  	ret = zynqmp_dma_chan_probe(zdev, pdev);
> @@ -1152,6 +1154,7 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
>  err_disable_pm:
>  	if (!pm_runtime_enabled(zdev->dev))
>  		zynqmp_dma_runtime_suspend(zdev->dev);
> +	pm_runtime_dont_use_autosuspend(zdev->dev);
>  	pm_runtime_disable(zdev->dev);
>  	return ret;
>  }
> @@ -1172,6 +1175,7 @@ static void zynqmp_dma_remove(struct platform_device *pdev)
>  	zynqmp_dma_chan_remove(zdev->chan);
>  	if (pm_runtime_active(zdev->dev))
>  		zynqmp_dma_runtime_suspend(zdev->dev);
> +	pm_runtime_dont_use_autosuspend(zdev->dev);
>  	pm_runtime_disable(zdev->dev);
>  }
>
> --
> 2.43.0
>