linux-kernel - [PATCH v1] PM: domains: Improve runtime PM performance state handling

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Date:   Mon, 23 Aug 2021 23:24:12 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Viresh Kumar <vireshk@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>, Nishanth Menon <nm@...com>
Cc:     linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: [PATCH v1] PM: domains: Improve runtime PM performance state handling

GENPD core doesn't support handling performance state changes while
consumer device is runtime-suspended or when runtime PM is disabled.
GENPD core may override performance state that was configured by device
driver while RPM of the device was disabled or device was RPM-suspended.
Let's close that gap by allowing drivers to control performance state
while RPM of a consumer device is disabled and to set up performance
state of RPM-suspended device that will be applied by GENPD core on
RPM-resume of the device.

Fixes: 5937c3ce2122 ("PM: domains: Drop/restore performance state votes for devices at runtime PM")
Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/base/power/domain.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index e1c8994ae225..3a13a942d012 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -435,7 +435,7 @@ static void genpd_restore_performance_state(struct device *dev,
 int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
 {
 	struct generic_pm_domain *genpd;
-	int ret;
+	int ret = 0;
 
 	genpd = dev_to_genpd_safe(dev);
 	if (!genpd)
@@ -446,7 +446,13 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
 		return -EINVAL;
 
 	genpd_lock(genpd);
-	ret = genpd_set_performance_state(dev, state);
+	if (pm_runtime_suspended(dev)) {
+		dev_gpd_data(dev)->rpm_pstate = state;
+	} else {
+		ret = genpd_set_performance_state(dev, state);
+		if (!ret)
+			dev_gpd_data(dev)->rpm_pstate = 0;
+	}
 	genpd_unlock(genpd);
 
 	return ret;
-- 
2.32.0