[PATCH V2 5/6] PM / domain: Save/restore performance state at runtime suspend/resume

Viresh Kumar
2017-02-09T03:48:42Z

With runtime PM, the devices get suspended while the system is up and
running in order to save power. At such times, it is important to
re-evaluate the required performance state of the domain, in order to
choose a lower state if possible.

This patch updates the genpd suspend/resume callbacks to do that.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/base/power/domain.c | 19 +++++++++++++++++--
include/linux/pm_domain.h | 1 +
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 1158a07f92de..ce9ab18be243 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -603,7 +603,8 @@ 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 *pd_data = dev_gpd_data(dev);
+ struct gpd_timing_data *td = &pd_data->td;
bool runtime_pm = pm_runtime_enabled(dev);
ktime_t time_start;
s64 elapsed_ns;
@@ -660,7 +661,14 @@ static int genpd_runtime_suspend(struct device *dev)
return 0;

genpd_lock(genpd);
+
+ /* Re-evaluate performance state of the domain */
+ pd_data->cached_performance_state = pd_data->performance_state;
+ pd_data->performance_state = 0;
+ update_domain_performance_state(genpd, 0);
+
genpd_power_off(genpd, false);
+
genpd_unlock(genpd);

return 0;
@@ -677,7 +685,8 @@ 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 *pd_data = dev_gpd_data(dev);
+ struct gpd_timing_data *td = &pd_data->td;
bool runtime_pm = pm_runtime_enabled(dev);
ktime_t time_start;
s64 elapsed_ns;
@@ -700,7 +709,13 @@ static int genpd_runtime_resume(struct device *dev)
}

genpd_lock(genpd);
+
ret = genpd_power_on(genpd, 0);
+
+ /* Re-evaluate performance state of the domain */
+ pd_data->performance_state = pd_data->cached_performance_state;
+ update_domain_performance_state(genpd, 0);
+
genpd_unlock(genpd);

if (ret)
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index d994ad5ba1c0..69b453d44adb 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -122,6 +122,7 @@ struct generic_pm_domain_data {
struct notifier_block nb;
struct notifier_block perf_nb;
unsigned int performance_state;
+ unsigned int cached_performance_state;
};

#ifdef CONFIG_PM_GENERIC_DOMAINS
--
2.7.1.410.g6faf27b