linux-kernel - [PATCH 4/4] cpufreq: Change order of online() CB and policy->cpus modification

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Date:   Wed, 15 Jun 2022 16:43:21 +0200
From:   Pierre Gondois <pierre.gondois@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Ionela.Voinescu@....com, Lukasz.Luba@....com,
        Dietmar.Eggemann@....com, Pierre Gondois <pierre.gondois@....com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        linux-pm@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: [PATCH 4/4] cpufreq: Change order of online() CB and policy->cpus modification

>From a state where all policy->related_cpus are offline, putting one
of the policy's CPU back online re-activates the policy by:
 1. Calling cpufreq_driver->online()
 2. Setting the CPU in policy->cpus

qcom_cpufreq_hw_cpu_online() makes use of policy->cpus. Thus 1. and 2.
should be inverted to avoid having a policy->cpus empty. The
qcom-cpufreq-hw is the only driver affected by this.

Fixes: a1eb080a0447 ("cpufreq: qcom-hw: provide online/offline operations")
Signed-off-by: Pierre Gondois <pierre.gondois@....com>
---
 drivers/cpufreq/cpufreq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2cad42774164..36043be16d8e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1350,15 +1350,15 @@ static int cpufreq_online(unsigned int cpu)
 	}
 
 	if (!new_policy && cpufreq_driver->online) {
+		/* Recover policy->cpus using related_cpus */
+		cpumask_copy(policy->cpus, policy->related_cpus);
+
 		ret = cpufreq_driver->online(policy);
 		if (ret) {
 			pr_debug("%s: %d: initialization failed\n", __func__,
 				 __LINE__);
 			goto out_exit_policy;
 		}
-
-		/* Recover policy->cpus using related_cpus */
-		cpumask_copy(policy->cpus, policy->related_cpus);
 	} else {
 		cpumask_copy(policy->cpus, cpumask_of(cpu));
 
-- 
2.25.1