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

[Frank Li <Frank.li@oss.nxp.com>]

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
>