Re: [PATCH] dmaengine: mediatek: hsdma: fix runtime PM leak on init failure

[Frank Li]

On Wed, Jun 24, 2026 at 05:16:38PM +0900, Myeonghun Pak wrote:
> mtk_hsdma_hw_init() enables runtime PM and gets a runtime PM reference
> before enabling the HSDMA clock. It currently ignores failures from
> pm_runtime_get_sync(); if runtime resume fails, the usage count remains
> held. If clk_prepare_enable() then fails, runtime PM is left enabled with
> the usage count held.
>
> Use pm_runtime_resume_and_get() so resume failures do not leak the usage
> count, and unwind runtime PM when clk_prepare_enable() fails.
>
> The probe path also ignores the return value from mtk_hsdma_hw_init(), so a
> failed hardware init can continue as a successful probe. Propagate
> mtk_hsdma_hw_init() failures from probe, while keeping a separate unwind
> label so mtk_hsdma_hw_deinit() is only called after hardware init succeeds.
>
> Fixes: 548c4597e984 ("dmaengine: mediatek: Add MediaTek High-Speed DMA controller for MT7622 and MT7623 SoC")
> Co-developed-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Myeonghun Pak <mhun512@xxxxxxxxx>
>
> ---
>  drivers/dma/mediatek/mtk-hsdma.c | 22 +++++++++++++++++-----
>  1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/mediatek/mtk-hsdma.c b/drivers/dma/mediatek/mtk-hsdma.c
> index a43412ff5e..987e5274fc 100644
> --- a/drivers/dma/mediatek/mtk-hsdma.c
> +++ b/drivers/dma/mediatek/mtk-hsdma.c
> @@ -849,16 +849,25 @@ static int mtk_hsdma_hw_init(struct mtk_hsdma_device *hsdma)
>  	int err;
>
>  	pm_runtime_enable(hsdma2dev(hsdma));

use devm_pm_runtime_enable()

> -	pm_runtime_get_sync(hsdma2dev(hsdma));
> +	err = pm_runtime_resume_and_get(hsdma2dev(hsdma));

It enable runtime pm and resume_get here. and suspend at driver remove,
so whole life cycle, pm is enable, why need enable runtime pm management?

Frank

> +	if (err < 0)
> +		goto err_disable_pm;
>
>  	err = clk_prepare_enable(hsdma->clk);
>  	if (err)
> -		return err;
> +		goto err_put_pm;
>
>  	mtk_dma_write(hsdma, MTK_HSDMA_INT_ENABLE, 0);
>  	mtk_dma_write(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DEFAULT);
>
>  	return 0;
> +
> +err_put_pm:
> +	pm_runtime_put_sync(hsdma2dev(hsdma));
> +err_disable_pm:
> +	pm_runtime_disable(hsdma2dev(hsdma));
> +
> +	return err;
>  }
>
>  static int mtk_hsdma_hw_deinit(struct mtk_hsdma_device *hsdma)
> @@ -983,7 +992,9 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
>  		goto err_unregister;
>  	}
>
> -	mtk_hsdma_hw_init(hsdma);
> +	err = mtk_hsdma_hw_init(hsdma);
> +	if (err)
> +		goto err_free;
>
>  	err = devm_request_irq(&pdev->dev, hsdma->irq,
>  			       mtk_hsdma_irq, 0,
> @@ -991,7 +1002,7 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
>  	if (err) {
>  		dev_err(&pdev->dev,
>  			"request_irq failed with err %d\n", err);
> -		goto err_free;
> +		goto err_deinit;
>  	}
>
>  	platform_set_drvdata(pdev, hsdma);
> @@ -1000,8 +1011,9 @@ static int mtk_hsdma_probe(struct platform_device *pdev)
>
>  	return 0;
>
> -err_free:
> +err_deinit:
>  	mtk_hsdma_hw_deinit(hsdma);
> +err_free:
>  	of_dma_controller_free(pdev->dev.of_node);
>  err_unregister:
>  	dma_async_device_unregister(dd);
> --
> 2.47.1