[PATCH 4.9 72/88] cpufreq: Restore policy min/max limits on CPU online

From: Greg Kroah-Hartman
Date: Tue Mar 28 2017 - 08:45:27 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

commit ff010472fb75670cb5c08671e820eeea3af59c87 upstream.

On CPU online the cpufreq core restores the previous governor (or
the previous "policy" setting for ->setpolicy drivers), but it does
not restore the min/max limits at the same time, which is confusing,
inconsistent and real pain for users who set the limits and then
suspend/resume the system (using full suspend), in which case the
limits are reset on all CPUs except for the boot one.

Fix this by making cpufreq_online() restore the limits when an inactive
policy is brought online.

The commit log and patch are inspired from Rafael's earlier work.

Reported-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/cpufreq/cpufreq.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1190,6 +1190,9 @@ static int cpufreq_online(unsigned int c
for_each_cpu(j, policy->related_cpus)
per_cpu(cpufreq_cpu_data, j) = policy;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ } else {
+ policy->min = policy->user_policy.min;
+ policy->max = policy->user_policy.max;
}

if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {