Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()

From: Vinod Koul
Date: Mon May 31 2021 - 00:01:35 EST


On 17-05-21, 16:18, Yu Kuai wrote:
> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here.
> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> counter balanced.
>
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> drivers/dma/sh/usb-dmac.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> index 8f7ceb698226..2a6c8fd8854e 100644
> --- a/drivers/dma/sh/usb-dmac.c
> +++ b/drivers/dma/sh/usb-dmac.c
> @@ -796,7 +796,7 @@ static int usb_dmac_probe(struct platform_device *pdev)
>
> /* Enable runtime PM and initialize the device. */
> pm_runtime_enable(&pdev->dev);
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = pm_runtime_resume_and_get(&pdev->dev);

This does not seem to fix anything.. the below goto goes and disables
the runtime_pm for this device and thus there wont be any leak

> if (ret < 0) {
> dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret);
> goto error_pm;
> --
> 2.25.4

--
~Vinod