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

From: Rafael J. Wysocki
Date: Thu Mar 16 2017 - 18:54:35 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

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_init_policy() restore the limits when it
sees that this is CPU online and not initialization from scratch.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -979,6 +979,8 @@ static int cpufreq_init_policy(struct cp
/* Update governor of new_policy to the governor used before hotplug */
gov = find_governor(policy->last_governor);
if (gov) {
+ new_policy.min = policy->user_policy.min;
+ new_policy.max = policy->user_policy.max;
pr_debug("Restoring governor %s for cpu %d\n",
policy->governor->name, policy->cpu);
} else {
@@ -991,11 +993,14 @@ static int cpufreq_init_policy(struct cp

/* Use the default policy if there is no last_policy. */
if (cpufreq_driver->setpolicy) {
- if (policy->last_policy)
+ if (policy->last_policy) {
new_policy.policy = policy->last_policy;
- else
+ new_policy.min = policy->user_policy.min;
+ new_policy.max = policy->user_policy.max;
+ } else {
cpufreq_parse_governor(gov->name, &new_policy.policy,
NULL);
+ }
}
/* set default policy */
return cpufreq_set_policy(policy, &new_policy);