linux-kernel - [PATCH 5/6] cpufreq: Preserve policy's boost state after resume

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Message-Id: <c4b9640ab104690c78766bcac6b047f72374b09b.1745315548.git.viresh.kumar@linaro.org>
Date: Tue, 22 Apr 2025 15:23:55 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: "Rafael J. Wysocki" <rafael@...nel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-pm@...r.kernel.org,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Lifeng Zheng <zhenglifeng1@...wei.com>,
	Nicholas Chin <nic.c3.14@...il.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 5/6] cpufreq: Preserve policy's boost state after resume

If the global boost flag was enabled and policy boost flag was disabled
before a suspend resume cycle, cpufreq_online() will enable the policy
boost flag on resume.

While it is important for the policy boost flag to mirror the global
boost flag when a policy is first created, it should be avoided when the
policy is reinitialized (for example after a suspend resume cycle).

Though, if the global boost flag is disabled at this point of time, we
want to make sure policy boost flag is disabled too.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/cpufreq.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 24745088403b..0ad459bc8f84 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1626,8 +1626,13 @@ static int cpufreq_online(unsigned int cpu)
 	if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver))
 		policy->cdev = of_cpufreq_cooling_register(policy);
 
-	/* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
-	if (cpufreq_driver->set_boost && policy->boost_supported) {
+	/*
+	 * Let the per-policy boost flag mirror the cpufreq_driver boost during
+	 * initialization for a new policy. For an existing policy, maintain the
+	 * previous boost value unless global boost is disabled.
+	 */
+	if (cpufreq_driver->set_boost && policy->boost_supported &&
+	    (new_policy || !cpufreq_boost_enabled())) {
 		ret = policy_set_boost(policy, cpufreq_boost_enabled());
 		if (ret) {
 			/* If the set_boost fails, the online operation is not affected */
-- 
2.31.1.272.g89b43f80a514