On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote: > On 31-05-21, 14:11, yukuai (C) wrote: > > On 2021/05/31 12:00, Vinod Koul wrote: > > > 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 > > Hi, > > > > If pm_runtime_get_sync() fails and increments the pm.usage_count > > variable, pm_runtime_disable() does not reset the counter, and > > we still need to decrement the usage count when pm_runtime_get_sync() > > fails. Do I miss anthing? > > Yes the rumtime_pm is disabled on failure here and the count would have > no consequence... You should still balance the PM usage counter as it isn't reset for example when reloading the driver. Using pm_runtime_resume_and_get() is one way of handling this, but alternatively you could also move the error_pm label above the pm_runtime_put() in the error path. Johan
