Re: [PATCH] dmaengine: qcom_hidma: Fix runtime PM leak in hidma_issue_task()

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

On Wed, Sep 16, 2026 at 09:30:32AM +0000, Wentao Liang wrote:
> [You don't often get email from vulab@iscas.ac.cn. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> hidma_issue_task() bumps the device usage counter with
> pm_runtime_get_sync() without checking the return value. The counter
> is incremented even when the resume fails, e.g. when runtime PM has
> been disabled or the device is suspending, and nothing drops it in
> that case, so each failure leaves the device with an elevated usage
> count and it can no longer runtime suspend.
>
> Bail out and drop the leaked increment with pm_runtime_put_noidle()
> when the resume fails, and only start the transfer when the device is
> actually resumed. The counter for a successful resume is still
> dropped by hidma_callback() as before.
>
> Fixes: 67a2003e0607 ("dmaengine: add Qualcomm Technologies HIDMA channel driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  drivers/dma/qcom/hidma.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
> index 5a8dca8db5ce..03a73dc9b066 100644
> --- a/drivers/dma/qcom/hidma.c
> +++ b/drivers/dma/qcom/hidma.c
> @@ -220,7 +220,10 @@ static void hidma_issue_task(struct tasklet_struct *t)
>  {
>         struct hidma_dev *dmadev = from_tasklet(dmadev, t, task);
>
> -       pm_runtime_get_sync(dmadev->ddev.dev);
> +       if (pm_runtime_get_sync(dmadev->ddev.dev) < 0) {

use pm_runtime_resume_and_get()

Frank

> +               pm_runtime_put_noidle(dmadev->ddev.dev);
> +               return;
> +       }
>         hidma_ll_start(dmadev->lldev);
>  }
>
> --
> 2.34.1
>