On Wed, May 20, 2020 at 01:15:44PM +0300, Dmitry Osipenko wrote: > 20.05.2020 12:51, Dinghao Liu пишет: > > pm_runtime_get_sync() increments the runtime PM usage counter even > > it returns an error code. Thus a pairing decrement is needed on > > the error handling path to keep the counter balanced. > > > > Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx> > > --- > > drivers/staging/media/tegra-vde/vde.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c > > index d3e63512a765..dd134a3a15c7 100644 > > --- a/drivers/staging/media/tegra-vde/vde.c > > +++ b/drivers/staging/media/tegra-vde/vde.c > > @@ -777,7 +777,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, > > > > ret = pm_runtime_get_sync(dev); > > if (ret < 0) > > - goto unlock; > > + goto put_runtime_pm; > > > > /* > > * We rely on the VDE registers reset value, otherwise VDE > > > > Hello Dinghao, > > Thank you for the patch. I sent out a similar patch a week ago [1]. > > [1] > https://patchwork.ozlabs.org/project/linux-tegra/patch/20200514210847.9269-2-digetx@xxxxxxxxx/ > > The pm_runtime_put_noidle() should have the same effect as yours > variant, although my variant won't change the last_busy RPM time, which > I think is a bit more appropriate behavior. I don't think either patch is correct. The right thing to do is to fix __pm_runtime_resume() so it doesn't leak a reference count on error. The problem is that a lot of functions don't check the return so possibly we are relying on that behavior. We may need to introduce a new function which cleans up properly instead of leaking reference counts? Also it's not documented that pm_runtime_get_sync() returns 1 sometimes on success so it leads to a few bugs. drivers/gpu/drm/stm/ltdc.c: ret = pm_runtime_get_sync(ddev->dev); drivers/gpu/drm/stm/ltdc.c- if (ret) { -- drivers/gpu/drm/stm/ltdc.c: ret = pm_runtime_get_sync(ddev->dev); drivers/gpu/drm/stm/ltdc.c- if (ret) { drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c: ret = pm_runtime_get_sync(pm->dev); drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c- if (ret) drivers/media/platform/ti-vpe/cal.c: ret = pm_runtime_get_sync(&pdev->dev); drivers/media/platform/ti-vpe/cal.c- if (ret) drivers/mfd/arizona-core.c: ret = pm_runtime_get_sync(arizona->dev); drivers/mfd/arizona-core.c- if (ret != 0) drivers/remoteproc/qcom_q6v5_adsp.c: ret = pm_runtime_get_sync(adsp->dev); drivers/remoteproc/qcom_q6v5_adsp.c- if (ret) drivers/spi/spi-img-spfi.c: ret = pm_runtime_get_sync(dev); drivers/spi/spi-img-spfi.c- if (ret) drivers/usb/dwc3/dwc3-pci.c: ret = pm_runtime_get_sync(&dwc3->dev); drivers/usb/dwc3/dwc3-pci.c- if (ret) drivers/watchdog/rti_wdt.c: ret = pm_runtime_get_sync(dev); drivers/watchdog/rti_wdt.c- if (ret) { regards, dan carpenter diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 99c7da112c95..e280991a977d 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1082,6 +1082,9 @@ int __pm_runtime_resume(struct device *dev, int rpmflags) retval = rpm_resume(dev, rpmflags); spin_unlock_irqrestore(&dev->power.lock, flags); + if (retval < 0 && rpmflags & RPM_GET_PUT) + atomic_dec(&dev->power.usage_count); + return retval; } EXPORT_SYMBOL_GPL(__pm_runtime_resume);
