| Message ID | d7fb2d00224d37ba1c6c6e9b73609af95c886844.1619519080.git.mchehab+huawei@kernel.org |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Address some issues with PM runtime at media subsystem | expand |
27.04.2021 13:26, Mauro Carvalho Chehab пишет: > @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev) > { > struct tegra_vde *vde = platform_get_drvdata(pdev); > struct device *dev = &pdev->dev; > + int ret; > > - pm_runtime_get_sync(dev); > + ret = pm_runtime_resume_and_get(dev); Should be cleaner to return error directly here, IMO. > pm_runtime_dont_use_autosuspend(dev); > pm_runtime_disable(dev); > > @@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev) > * Balance RPM state, the VDE power domain is left ON and hardware > * is clock-gated. It's safe to reboot machine now. > */ > - pm_runtime_put_noidle(dev); > + if (ret >= 0) > + pm_runtime_put_noidle(dev); > clk_disable_unprepare(vde->clk);
Em Tue, 27 Apr 2021 14:47:01 +0300 Dmitry Osipenko <digetx@gmail.com> escreveu: > 27.04.2021 13:26, Mauro Carvalho Chehab пишет: > > @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev) > > { > > struct tegra_vde *vde = platform_get_drvdata(pdev); > > struct device *dev = &pdev->dev; > > + int ret; > > > > - pm_runtime_get_sync(dev); > > + ret = pm_runtime_resume_and_get(dev); > > Should be cleaner to return error directly here, IMO. I double-checked how drivers/base/platform.c deals with non-zero returns at the .remove method: static int platform_remove(struct device *_dev) { struct platform_driver *drv = to_platform_driver(_dev->driver); struct platform_device *dev = to_platform_device(_dev); if (drv->remove) { int ret = drv->remove(dev); if (ret) dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n"); } dev_pm_domain_detach(_dev, true); return 0; } Basically, it will print a message but will ignore whatever happens afterwards. So, if the driver is changed to return an error there, it will leak resources. Thanks, Mauro
28.04.2021 10:20, Mauro Carvalho Chehab пишет: > Em Tue, 27 Apr 2021 14:47:01 +0300 > Dmitry Osipenko <digetx@gmail.com> escreveu: > >> 27.04.2021 13:26, Mauro Carvalho Chehab пишет: >>> @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev) >>> { >>> struct tegra_vde *vde = platform_get_drvdata(pdev); >>> struct device *dev = &pdev->dev; >>> + int ret; >>> >>> - pm_runtime_get_sync(dev); >>> + ret = pm_runtime_resume_and_get(dev); >> >> Should be cleaner to return error directly here, IMO. > > I double-checked how drivers/base/platform.c deals with non-zero > returns at the .remove method: > > static int platform_remove(struct device *_dev) > { > struct platform_driver *drv = to_platform_driver(_dev->driver); > struct platform_device *dev = to_platform_device(_dev); > > if (drv->remove) { > int ret = drv->remove(dev); > > if (ret) > dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n"); > } > dev_pm_domain_detach(_dev, true); > > return 0; > } > > Basically, it will print a message but will ignore whatever happens > afterwards. > > So, if the driver is changed to return an error there, it will leak > resources. Indeed, thank you. But then the pm_runtime_get_sync() should be more appropriate since this function is specifically made for such cases where returned value is ignored. A better option could be better to add a clarifying comment to the code rather than to change it to a variant which introduces confusion, IMO.
diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c index 28845b5bafaf..8936f140a246 100644 --- a/drivers/staging/media/tegra-vde/vde.c +++ b/drivers/staging/media/tegra-vde/vde.c @@ -775,9 +775,9 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, if (ret) goto release_dpb_frames; - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) - goto put_runtime_pm; + goto unlock; /* * We rely on the VDE registers reset value, otherwise VDE @@ -843,6 +843,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, put_runtime_pm: pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); + +unlock: mutex_unlock(&vde->lock); release_dpb_frames: @@ -1069,8 +1071,8 @@ static int tegra_vde_probe(struct platform_device *pdev) * power-cycle it in order to put hardware into a predictable lower * power state. */ - pm_runtime_get_sync(dev); - pm_runtime_put(dev); + if (pm_runtime_resume_and_get(dev) >= 0) + pm_runtime_put(dev); return 0; @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev) { struct tegra_vde *vde = platform_get_drvdata(pdev); struct device *dev = &pdev->dev; + int ret; - pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); @@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev) * Balance RPM state, the VDE power domain is left ON and hardware * is clock-gated. It's safe to reboot machine now. */ - pm_runtime_put_noidle(dev); + if (ret >= 0) + pm_runtime_put_noidle(dev); clk_disable_unprepare(vde->clk); misc_deregister(&vde->miscdev);
Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") added pm_runtime_resume_and_get() in order to automatically handle dev->power.usage_count decrement on errors. Use the new API, in order to cleanup the error check logic. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> --- drivers/staging/media/tegra-vde/vde.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)