| Message ID | 9c7d683907b9f9cf4a99f57f978671ec7f5a1dbc.1619191723.git.mchehab+huawei@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | media: use pm_runtime_resume_and_get() instead of pm_runtime_get_sync() | expand |
On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: > 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- > drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > index 9f41c2e7097a..9d5841194f6b 100644 > --- a/drivers/media/platform/exynos-gsc/gsc-core.c > +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) > struct gsc_dev *gsc = platform_get_drvdata(pdev); > int i; > > - pm_runtime_get_sync(&pdev->dev); > + pm_runtime_resume_and_get(&pdev->dev); > > gsc_unregister_m2m_device(gsc); > v4l2_device_unregister(&gsc->v4l2_dev); > @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) > for (i = 0; i < gsc->num_clocks; i++) > clk_disable_unprepare(gsc->clock[i]); > > - pm_runtime_put_noidle(&pdev->dev); If we do this then the device usage count will not get decremented after the pm_runtime_resume_and_get() call above and after driver unload/load cycle it will not be possible to suspend the device. I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() works better in that case. Regards, Sylwester > pm_runtime_disable(&pdev->dev); > > dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name
Em Tue, 27 Apr 2021 10:18:12 +0200 Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: > > 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- > > drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- > > 2 files changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > > index 9f41c2e7097a..9d5841194f6b 100644 > > --- a/drivers/media/platform/exynos-gsc/gsc-core.c > > +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > > @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) > > struct gsc_dev *gsc = platform_get_drvdata(pdev); > > int i; > > > > - pm_runtime_get_sync(&pdev->dev); > > + pm_runtime_resume_and_get(&pdev->dev); > > > > gsc_unregister_m2m_device(gsc); > > v4l2_device_unregister(&gsc->v4l2_dev); > > @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) > > for (i = 0; i < gsc->num_clocks; i++) > > clk_disable_unprepare(gsc->clock[i]); > > > > - pm_runtime_put_noidle(&pdev->dev); > > If we do this then the device usage count will not get decremented > after the pm_runtime_resume_and_get() call above and after driver > unload/load cycle it will not be possible to suspend the device. > I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() > works better in that case. Good point. Actually, I don't see any reason why to call a PM resume function - either being pm_runtime_get_sync() or pm_runtime_resume_and_get(). The code there could simply be: static int gsc_remove(struct platform_device *pdev) { struct gsc_dev *gsc = platform_get_drvdata(pdev); int i; gsc_unregister_m2m_device(gsc); v4l2_device_unregister(&gsc->v4l2_dev); vb2_dma_contig_clear_max_seg_size(&pdev->dev); for (i = 0; i < gsc->num_clocks; i++) clk_disable_unprepare(gsc->clock[i]); pm_runtime_disable(&pdev->dev); dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); return 0; } Eventually also adding: pm_runtime_suspended(&pdev->dev); just after pm_runtime_disable(). Regards, Mauro
Em Tue, 27 Apr 2021 11:30:55 +0200 Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > Em Tue, 27 Apr 2021 10:18:12 +0200 > Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > > > On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: > > > 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- > > > drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- > > > 2 files changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > > > index 9f41c2e7097a..9d5841194f6b 100644 > > > --- a/drivers/media/platform/exynos-gsc/gsc-core.c > > > +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > > > @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) > > > struct gsc_dev *gsc = platform_get_drvdata(pdev); > > > int i; > > > > > > - pm_runtime_get_sync(&pdev->dev); > > > + pm_runtime_resume_and_get(&pdev->dev); > > > > > > gsc_unregister_m2m_device(gsc); > > > v4l2_device_unregister(&gsc->v4l2_dev); > > > @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) > > > for (i = 0; i < gsc->num_clocks; i++) > > > clk_disable_unprepare(gsc->clock[i]); > > > > > > - pm_runtime_put_noidle(&pdev->dev); > > > > If we do this then the device usage count will not get decremented > > after the pm_runtime_resume_and_get() call above and after driver > > unload/load cycle it will not be possible to suspend the device. > > I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() > > works better in that case. > > Good point. > > Actually, I don't see any reason why to call a PM resume > function - either being pm_runtime_get_sync() or > pm_runtime_resume_and_get(). > > The code there could simply be: > > static int gsc_remove(struct platform_device *pdev) > { > struct gsc_dev *gsc = platform_get_drvdata(pdev); > int i; > > gsc_unregister_m2m_device(gsc); > v4l2_device_unregister(&gsc->v4l2_dev); > > vb2_dma_contig_clear_max_seg_size(&pdev->dev); > for (i = 0; i < gsc->num_clocks; i++) > clk_disable_unprepare(gsc->clock[i]); > > pm_runtime_disable(&pdev->dev); > > dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); > return 0; > } > > Eventually also adding: > pm_runtime_suspended(&pdev->dev); In time: I actually meant: pm_runtime_set_suspended(&pdev->dev); but after double-checking the PM runtime code, it sounds to me that just calling pm_runtime_disable() would be enough. Not 100% sure here. Btw, some media drivers call it after pm_runtime_disable(), while others don't do. Thanks, Mauro
On 27.04.2021 11:42, Mauro Carvalho Chehab wrote: > Em Tue, 27 Apr 2021 11:30:55 +0200 > Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > >> Em Tue, 27 Apr 2021 10:18:12 +0200 >> Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: >> >>> On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: >>>> 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- >>>> drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- >>>> 2 files changed, 2 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c >>>> index 9f41c2e7097a..9d5841194f6b 100644 >>>> --- a/drivers/media/platform/exynos-gsc/gsc-core.c >>>> +++ b/drivers/media/platform/exynos-gsc/gsc-core.c >>>> @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) >>>> struct gsc_dev *gsc = platform_get_drvdata(pdev); >>>> int i; >>>> >>>> - pm_runtime_get_sync(&pdev->dev); >>>> + pm_runtime_resume_and_get(&pdev->dev); >>>> >>>> gsc_unregister_m2m_device(gsc); >>>> v4l2_device_unregister(&gsc->v4l2_dev); >>>> @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) >>>> for (i = 0; i < gsc->num_clocks; i++) >>>> clk_disable_unprepare(gsc->clock[i]); >>>> >>>> - pm_runtime_put_noidle(&pdev->dev); >>> >>> If we do this then the device usage count will not get decremented >>> after the pm_runtime_resume_and_get() call above and after driver >>> unload/load cycle it will not be possible to suspend the device. >>> I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() >>> works better in that case. >> >> Good point. >> >> Actually, I don't see any reason why to call a PM resume >> function - either being pm_runtime_get_sync() or >> pm_runtime_resume_and_get(). >> >> The code there could simply be: >> >> static int gsc_remove(struct platform_device *pdev) >> { >> struct gsc_dev *gsc = platform_get_drvdata(pdev); >> int i; >> >> gsc_unregister_m2m_device(gsc); >> v4l2_device_unregister(&gsc->v4l2_dev); >> >> vb2_dma_contig_clear_max_seg_size(&pdev->dev); >> for (i = 0; i < gsc->num_clocks; i++) >> clk_disable_unprepare(gsc->clock[i]); >> >> pm_runtime_disable(&pdev->dev); >> >> dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); >> return 0; >> } >> >> Eventually also adding: >> pm_runtime_suspended(&pdev->dev); > > In time: I actually meant: > > pm_runtime_set_suspended(&pdev->dev); > > but after double-checking the PM runtime code, it sounds to me that > just calling pm_runtime_disable() would be enough. Not 100% sure > here. Btw, some media drivers call it after pm_runtime_disable(), > while others don't do. I think if the device is brought into suspended state (e.g. by disabling clocks as above) the pm_runtime_set_suspended() call should be there. IOW a following sequence: pm_runtime_disable(dev); if (!pm_runtime_status_suspended(dev)) /* put device into suspended state (disable clocks, voltage regulators, assert GPIOs, etc. */ pm_runtime_set_suspended(dev); -- Regards, Sylwester
Em Tue, 27 Apr 2021 13:50:44 +0200 Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > On 27.04.2021 11:42, Mauro Carvalho Chehab wrote: > > Em Tue, 27 Apr 2021 11:30:55 +0200 > > Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > > > >> Em Tue, 27 Apr 2021 10:18:12 +0200 > >> Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > >> > >>> On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: > >>>> 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- > >>>> drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- > >>>> 2 files changed, 2 insertions(+), 3 deletions(-) > >>>> > >>>> diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > >>>> index 9f41c2e7097a..9d5841194f6b 100644 > >>>> --- a/drivers/media/platform/exynos-gsc/gsc-core.c > >>>> +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > >>>> @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) > >>>> struct gsc_dev *gsc = platform_get_drvdata(pdev); > >>>> int i; > >>>> > >>>> - pm_runtime_get_sync(&pdev->dev); > >>>> + pm_runtime_resume_and_get(&pdev->dev); > >>>> > >>>> gsc_unregister_m2m_device(gsc); > >>>> v4l2_device_unregister(&gsc->v4l2_dev); > >>>> @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) > >>>> for (i = 0; i < gsc->num_clocks; i++) > >>>> clk_disable_unprepare(gsc->clock[i]); > >>>> > >>>> - pm_runtime_put_noidle(&pdev->dev); > >>> > >>> If we do this then the device usage count will not get decremented > >>> after the pm_runtime_resume_and_get() call above and after driver > >>> unload/load cycle it will not be possible to suspend the device. > >>> I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() > >>> works better in that case. > >> > >> Good point. > >> > >> Actually, I don't see any reason why to call a PM resume > >> function - either being pm_runtime_get_sync() or > >> pm_runtime_resume_and_get(). > >> > >> The code there could simply be: > >> > >> static int gsc_remove(struct platform_device *pdev) > >> { > >> struct gsc_dev *gsc = platform_get_drvdata(pdev); > >> int i; > >> > >> gsc_unregister_m2m_device(gsc); > >> v4l2_device_unregister(&gsc->v4l2_dev); > >> > >> vb2_dma_contig_clear_max_seg_size(&pdev->dev); > >> for (i = 0; i < gsc->num_clocks; i++) > >> clk_disable_unprepare(gsc->clock[i]); > >> > >> pm_runtime_disable(&pdev->dev); > >> > >> dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); > >> return 0; > >> } > >> > >> Eventually also adding: > >> pm_runtime_suspended(&pdev->dev); > > > > In time: I actually meant: > > > > pm_runtime_set_suspended(&pdev->dev); > > > > but after double-checking the PM runtime code, it sounds to me that > > just calling pm_runtime_disable() would be enough. Not 100% sure > > here. Btw, some media drivers call it after pm_runtime_disable(), > > while others don't do. > > I think if the device is brought into suspended state (e.g. by > disabling clocks as above) the pm_runtime_set_suspended() call > should be there. IOW a following sequence: > > pm_runtime_disable(dev); > if (!pm_runtime_status_suspended(dev)) > /* put device into suspended state (disable clocks, > voltage regulators, assert GPIOs, etc. */ > pm_runtime_set_suspended(dev); Not sure if this would work, as the clock framework would try to do things like calling clk_pm_runtime_put(). Perhaps an alternative would be to just return an error if it can't resume PM runtime, e. g.: diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c index 9f41c2e7097a..d47d02c75484 100644 --- a/drivers/media/platform/exynos-gsc/gsc-core.c +++ b/drivers/media/platform/exynos-gsc/gsc-core.c @@ -1208,9 +1208,11 @@ static int gsc_probe(struct platform_device *pdev) static int gsc_remove(struct platform_device *pdev) { struct gsc_dev *gsc = platform_get_drvdata(pdev); - int i; + int ret, i; - pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) + return ret; gsc_unregister_m2m_device(gsc); v4l2_device_unregister(&gsc->v4l2_dev); Thanks, Mauro
Em Wed, 28 Apr 2021 09:13:02 +0200 Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > Em Tue, 27 Apr 2021 13:50:44 +0200 > Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > > > On 27.04.2021 11:42, Mauro Carvalho Chehab wrote: > > > Em Tue, 27 Apr 2021 11:30:55 +0200 > > > Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > > > > > >> Em Tue, 27 Apr 2021 10:18:12 +0200 > > >> Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: > > >> > > >>> On 24.04.2021 08:45, Mauro Carvalho Chehab wrote: > > >>>> 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/media/platform/exynos-gsc/gsc-core.c | 3 +-- > > >>>> drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- > > >>>> 2 files changed, 2 insertions(+), 3 deletions(-) > > >>>> > > >>>> diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > > >>>> index 9f41c2e7097a..9d5841194f6b 100644 > > >>>> --- a/drivers/media/platform/exynos-gsc/gsc-core.c > > >>>> +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > > >>>> @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) > > >>>> struct gsc_dev *gsc = platform_get_drvdata(pdev); > > >>>> int i; > > >>>> > > >>>> - pm_runtime_get_sync(&pdev->dev); > > >>>> + pm_runtime_resume_and_get(&pdev->dev); > > >>>> > > >>>> gsc_unregister_m2m_device(gsc); > > >>>> v4l2_device_unregister(&gsc->v4l2_dev); > > >>>> @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) > > >>>> for (i = 0; i < gsc->num_clocks; i++) > > >>>> clk_disable_unprepare(gsc->clock[i]); > > >>>> > > >>>> - pm_runtime_put_noidle(&pdev->dev); > > >>> > > >>> If we do this then the device usage count will not get decremented > > >>> after the pm_runtime_resume_and_get() call above and after driver > > >>> unload/load cycle it will not be possible to suspend the device. > > >>> I wouldn't be changing anything in gsc_remove(), pm_runtime_get_sync() > > >>> works better in that case. > > >> > > >> Good point. > > >> > > >> Actually, I don't see any reason why to call a PM resume > > >> function - either being pm_runtime_get_sync() or > > >> pm_runtime_resume_and_get(). > > >> > > >> The code there could simply be: > > >> > > >> static int gsc_remove(struct platform_device *pdev) > > >> { > > >> struct gsc_dev *gsc = platform_get_drvdata(pdev); > > >> int i; > > >> > > >> gsc_unregister_m2m_device(gsc); > > >> v4l2_device_unregister(&gsc->v4l2_dev); > > >> > > >> vb2_dma_contig_clear_max_seg_size(&pdev->dev); > > >> for (i = 0; i < gsc->num_clocks; i++) > > >> clk_disable_unprepare(gsc->clock[i]); > > >> > > >> pm_runtime_disable(&pdev->dev); > > >> > > >> dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); > > >> return 0; > > >> } > > >> > > >> Eventually also adding: > > >> pm_runtime_suspended(&pdev->dev); > > > > > > In time: I actually meant: > > > > > > pm_runtime_set_suspended(&pdev->dev); > > > > > > but after double-checking the PM runtime code, it sounds to me that > > > just calling pm_runtime_disable() would be enough. Not 100% sure > > > here. Btw, some media drivers call it after pm_runtime_disable(), > > > while others don't do. > > > > I think if the device is brought into suspended state (e.g. by > > disabling clocks as above) the pm_runtime_set_suspended() call > > should be there. IOW a following sequence: > > > > pm_runtime_disable(dev); > > if (!pm_runtime_status_suspended(dev)) > > /* put device into suspended state (disable clocks, > > voltage regulators, assert GPIOs, etc. */ > > pm_runtime_set_suspended(dev); > > Not sure if this would work, as the clock framework would try > to do things like calling clk_pm_runtime_put(). > > Perhaps an alternative would be to just return an error if it > can't resume PM runtime, e. g.: > > diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c > index 9f41c2e7097a..d47d02c75484 100644 > --- a/drivers/media/platform/exynos-gsc/gsc-core.c > +++ b/drivers/media/platform/exynos-gsc/gsc-core.c > @@ -1208,9 +1208,11 @@ static int gsc_probe(struct platform_device *pdev) > static int gsc_remove(struct platform_device *pdev) > { > struct gsc_dev *gsc = platform_get_drvdata(pdev); > - int i; > + int ret, i; > > - pm_runtime_get_sync(&pdev->dev); > + ret = pm_runtime_resume_and_get(&pdev->dev); > + if (ret < 0) > + return ret; Nah, forget about that. Despite the platform driver having a return code, support for it bogus: 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; } Thanks, Mauro
On 28.04.2021 09:17, Mauro Carvalho Chehab wrote: > Em Wed, 28 Apr 2021 09:13:02 +0200 > Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu: > >> Em Tue, 27 Apr 2021 13:50:44 +0200 >> Sylwester Nawrocki <s.nawrocki@samsung.com> escreveu: >> >>> On 27.04.2021 11:42, Mauro Carvalho Chehab wrote: >>> I think if the device is brought into suspended state (e.g. by >>> disabling clocks as above) the pm_runtime_set_suspended() call >>> should be there. IOW a following sequence: >>> >>> pm_runtime_disable(dev); >>> if (!pm_runtime_status_suspended(dev)) >>> /* put device into suspended state (disable clocks, >>> voltage regulators, assert GPIOs, etc. */ >>> pm_runtime_set_suspended(dev); >> >> Not sure if this would work, as the clock framework would try >> to do things like calling clk_pm_runtime_put(). It's done in multiple drivers this way. clk_pm_runtime_put() operates on different device - the clock supplier, not the consumer device. We just need to disable runtime PM for GSC as the last step, to avoid any possible v4l2 m2m device_run() call with runtime PM disabled. >> Perhaps an alternative would be to just return an error if it >> can't resume PM runtime, e. g.: [...] > Nah, forget about that. Despite the platform driver having a return code, > support for it bogus: Yes, we can't really stop remove() from driver level so as much complete resource release is being done as possible. Regards, Sylwester
diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c index 9f41c2e7097a..9d5841194f6b 100644 --- a/drivers/media/platform/exynos-gsc/gsc-core.c +++ b/drivers/media/platform/exynos-gsc/gsc-core.c @@ -1210,7 +1210,7 @@ static int gsc_remove(struct platform_device *pdev) struct gsc_dev *gsc = platform_get_drvdata(pdev); int i; - pm_runtime_get_sync(&pdev->dev); + pm_runtime_resume_and_get(&pdev->dev); gsc_unregister_m2m_device(gsc); v4l2_device_unregister(&gsc->v4l2_dev); @@ -1219,7 +1219,6 @@ static int gsc_remove(struct platform_device *pdev) for (i = 0; i < gsc->num_clocks; i++) clk_disable_unprepare(gsc->clock[i]); - pm_runtime_put_noidle(&pdev->dev); pm_runtime_disable(&pdev->dev); dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name); diff --git a/drivers/media/platform/exynos-gsc/gsc-m2m.c b/drivers/media/platform/exynos-gsc/gsc-m2m.c index 27a3c92c73bc..09551e96ac15 100644 --- a/drivers/media/platform/exynos-gsc/gsc-m2m.c +++ b/drivers/media/platform/exynos-gsc/gsc-m2m.c @@ -58,7 +58,7 @@ static int gsc_m2m_start_streaming(struct vb2_queue *q, unsigned int count) struct gsc_ctx *ctx = q->drv_priv; int ret; - ret = pm_runtime_get_sync(&ctx->gsc_dev->pdev->dev); + ret = pm_runtime_resume_and_get(&ctx->gsc_dev->pdev->dev); return ret > 0 ? 0 : ret; }
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/media/platform/exynos-gsc/gsc-core.c | 3 +-- drivers/media/platform/exynos-gsc/gsc-m2m.c | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-)