| Message ID | 20211029123855.80344-1-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] PM: sleep: Fix runtime PM based cpuidle support | expand |
On Fri, Oct 29, 2021 at 2:39 PM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > In the cpuidle-psci case, runtime PM in combination with the generic PM > domain (genpd), may be used when entering/exiting a shared idlestate. More > precisely, genpd relies on runtime PM to be enabled for the attached device > (in this case it belongs to a CPU), to properly manage the reference > counting of its PM domain. > > This works fine most of the time, but during system suspend in > dpm_suspend_late(), the PM core disables runtime PM for all devices. Beyond > this point, calls to pm_runtime_get_sync() to runtime resume a device may > fail and therefore it could also mess up the reference counting in genpd. > > To fix this problem, let's call wake_up_all_idle_cpus() in > dpm_suspend_late(), prior to disabling runtime PM. In this way a device > that belongs to a CPU, becomes runtime resumed through cpuidle-psci and > stays like that, because the runtime PM usage count has been bumped in > device_prepare(). > > Diagnosed-by: Maulik Shah <mkshah@codeaurora.org> > Suggested-by: Rafael J. Wysocki <rafael@kernel.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v2: > - Moved away from using cpuidle_pause|resume() to solve the problem, but > instead just waking up idle CPUs is suffient, due to other recent merged > changes. > > --- > drivers/base/power/main.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index ac4dde8fdb8b..2fb08d4f1aca 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -1463,6 +1463,7 @@ int dpm_suspend_late(pm_message_t state) > int error = 0; > > trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true); > + wake_up_all_idle_cpus(); > mutex_lock(&dpm_list_mtx); > pm_transition = state; > async_error = 0; > -- Applied as 5.16-rc material, thanks!
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index ac4dde8fdb8b..2fb08d4f1aca 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1463,6 +1463,7 @@ int dpm_suspend_late(pm_message_t state) int error = 0; trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true); + wake_up_all_idle_cpus(); mutex_lock(&dpm_list_mtx); pm_transition = state; async_error = 0;
In the cpuidle-psci case, runtime PM in combination with the generic PM domain (genpd), may be used when entering/exiting a shared idlestate. More precisely, genpd relies on runtime PM to be enabled for the attached device (in this case it belongs to a CPU), to properly manage the reference counting of its PM domain. This works fine most of the time, but during system suspend in dpm_suspend_late(), the PM core disables runtime PM for all devices. Beyond this point, calls to pm_runtime_get_sync() to runtime resume a device may fail and therefore it could also mess up the reference counting in genpd. To fix this problem, let's call wake_up_all_idle_cpus() in dpm_suspend_late(), prior to disabling runtime PM. In this way a device that belongs to a CPU, becomes runtime resumed through cpuidle-psci and stays like that, because the runtime PM usage count has been bumped in device_prepare(). Diagnosed-by: Maulik Shah <mkshah@codeaurora.org> Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- Changes in v2: - Moved away from using cpuidle_pause|resume() to solve the problem, but instead just waking up idle CPUs is suffient, due to other recent merged changes. --- drivers/base/power/main.c | 1 + 1 file changed, 1 insertion(+)