From 5937c3ce21228d33d2eb3287baa7e4cf6978dba9 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Thu, 3 Jun 2021 11:34:37 +0200 Subject: PM: domains: Drop/restore performance state votes for devices at runtime PM A subsystem/driver that need to manage OPPs for its device, should typically drop its vote for the OPP when the device becomes runtime suspended. In this way, the corresponding aggregation of the performance state votes that is managed in genpd for the attached PM domain, may find that the aggregated vote can be decreased. Hence, it may allow genpd to set the lower performance state for the PM domain, thus avoiding to waste energy. To accomplish this, typically a subsystem/driver would need to call dev_pm_opp_set_rate|opp() for its device from its ->runtime_suspend() callback, to drop the vote for the OPP. Accordingly, it needs another call to dev_pm_opp_set_rate|opp() to restore the vote for the OPP from its ->runtime_resume() callback. To avoid boilerplate code in subsystems/driver to deal with these things, let's instead manage this internally in genpd. Signed-off-by: Ulf Hansson Tested-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'drivers/base/power') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 90a9828fcb2f..ab0b740cc0f1 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -400,6 +400,23 @@ static int genpd_set_performance_state(struct device *dev, unsigned int state) return ret; } +static int genpd_drop_performance_state(struct device *dev) +{ + unsigned int prev_state = dev_gpd_data(dev)->performance_state; + + if (!genpd_set_performance_state(dev, 0)) + return prev_state; + + return 0; +} + +static void genpd_restore_performance_state(struct device *dev, + unsigned int state) +{ + if (state) + genpd_set_performance_state(dev, state); +} + /** * dev_pm_genpd_set_performance_state- Set performance state of device's power * domain. @@ -843,7 +860,8 @@ static int genpd_runtime_suspend(struct device *dev) { struct generic_pm_domain *genpd; bool (*suspend_ok)(struct device *__dev); - struct gpd_timing_data *td = &dev_gpd_data(dev)->td; + struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev); + struct gpd_timing_data *td = &gpd_data->td; bool runtime_pm = pm_runtime_enabled(dev); ktime_t time_start; s64 elapsed_ns; @@ -900,6 +918,7 @@ static int genpd_runtime_suspend(struct device *dev) return 0; genpd_lock(genpd); + gpd_data->rpm_pstate = genpd_drop_performance_state(dev); genpd_power_off(genpd, true, 0); genpd_unlock(genpd); @@ -917,7 +936,8 @@ static int genpd_runtime_suspend(struct device *dev) static int genpd_runtime_resume(struct device *dev) { struct generic_pm_domain *genpd; - struct gpd_timing_data *td = &dev_gpd_data(dev)->td; + struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev); + struct gpd_timing_data *td = &gpd_data->td; bool runtime_pm = pm_runtime_enabled(dev); ktime_t time_start; s64 elapsed_ns; @@ -941,6 +961,8 @@ static int genpd_runtime_resume(struct device *dev) genpd_lock(genpd); ret = genpd_power_on(genpd, 0); + if (!ret) + genpd_restore_performance_state(dev, gpd_data->rpm_pstate); genpd_unlock(genpd); if (ret) @@ -979,6 +1001,7 @@ err_stop: err_poweroff: if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) { genpd_lock(genpd); + gpd_data->rpm_pstate = genpd_drop_performance_state(dev); genpd_power_off(genpd, true, 0); genpd_unlock(genpd); } -- cgit v1.2.3