| Message ID | 20221213155448.385167-1-rf@opensource.cirrus.com |
|---|---|
| State | Accepted |
| Commit | 450316dc4f41e857c928dfbcc495c3810d4b1928 |
| Headers | show |
| Series | PM: runtime: Document that force_suspend() is incompatible with SMART_SUSPEND | expand |
On Tue, Dec 13, 2022 at 4:54 PM Richard Fitzgerald <rf@opensource.cirrus.com> wrote: > > pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND, so > note this in the kerneldoc. > > If DPM_FLAG_SMART_SUSPEND is set and the PM core cannot skip system resume > it will call pm_runtime_active() on the driver. This can lead to an > inconsistent state where: > > pm_runtime_force_suspend() called ->runtime_suspend > > but > > device_resume_noirq() called pm_runtime_set_active() > > This leaves the driver actually suspended but marked as active. > > Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> > --- > drivers/base/power/runtime.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > index 50e726b6c2cf..b29be7d4d7d0 100644 > --- a/drivers/base/power/runtime.c > +++ b/drivers/base/power/runtime.c > @@ -1864,6 +1864,10 @@ static bool pm_runtime_need_not_resume(struct device *dev) > * sure the device is put into low power state and it should only be used during > * system-wide PM transitions to sleep states. It assumes that the analogous > * pm_runtime_force_resume() will be used to resume the device. > + * > + * Do not use with DPM_FLAG_SMART_SUSPEND as this can lead to an inconsistent > + * state where this function has called the ->runtime_suspend callback but the > + * PM core marks the driver as runtime active. > */ > int pm_runtime_force_suspend(struct device *dev) > { > -- Applied as 6.3 material, thanks!
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 50e726b6c2cf..b29be7d4d7d0 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1864,6 +1864,10 @@ static bool pm_runtime_need_not_resume(struct device *dev) * sure the device is put into low power state and it should only be used during * system-wide PM transitions to sleep states. It assumes that the analogous * pm_runtime_force_resume() will be used to resume the device. + * + * Do not use with DPM_FLAG_SMART_SUSPEND as this can lead to an inconsistent + * state where this function has called the ->runtime_suspend callback but the + * PM core marks the driver as runtime active. */ int pm_runtime_force_suspend(struct device *dev) {
pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND, so note this in the kerneldoc. If DPM_FLAG_SMART_SUSPEND is set and the PM core cannot skip system resume it will call pm_runtime_active() on the driver. This can lead to an inconsistent state where: pm_runtime_force_suspend() called ->runtime_suspend but device_resume_noirq() called pm_runtime_set_active() This leaves the driver actually suspended but marked as active. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> --- drivers/base/power/runtime.c | 4 ++++ 1 file changed, 4 insertions(+)