[PATCH v2 2/4] PM: domains: Return early if perf state is already set for the device

From: Ulf Hansson <ulf.hansson@linaro.org>
To: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	linux-pm@vger.kernel.org
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Dmitry Osipenko <digetx@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	Stephan Gerhold <stephan@gerhold.net>,
	Roja Rani Yarubandi <rojay@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Stephen Boyd <sboyd@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/4] PM: domains: Return early if perf state is already set for the device
Date: Thu,  3 Jun 2021 11:34:36 +0200	[thread overview]
Message-ID: <20210603093438.138705-3-ulf.hansson@linaro.org> (raw)
In-Reply-To: <20210603093438.138705-1-ulf.hansson@linaro.org>

When dev_pm_genpd_set_performance_state() gets called to set a new
performance state for the device, let's take a quicker path by doing an
early return, if it turns out that the new state is already set for the
device.

Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---

Changes in v2:
	- New patch.

---
 drivers/base/power/domain.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 5c476ed1c6c9..ef25a5b18587 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -387,6 +387,9 @@ static int genpd_set_performance_state(struct device *dev, unsigned int state)
 	int ret;
 
 	prev_state = gpd_data->performance_state;
+	if (prev_state == state)
+		return 0;
+
 	gpd_data->performance_state = state;
 	state = _genpd_reeval_performance_state(genpd, state);
 
-- 
2.25.1

