cpufreq: Don't call __cpufreq_governor() for drivers without target()
Some cpufreq drivers implement their own governor and so don't need
us to call generic governors interface via __cpufreq_governor(). Few
recent commits haven't obeyed this law well and we saw some
regressions.
This patch is an attempt to fix the above issue.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 3564947..a6f6595 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -858,13 +858,18 @@
struct device *dev)
{
struct cpufreq_policy *policy;
- int ret = 0;
+ int ret = 0, has_target = 0;
unsigned long flags;
policy = cpufreq_cpu_get(sibling);
WARN_ON(!policy);
- __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+ rcu_read_lock();
+ has_target = !!rcu_dereference(cpufreq_driver)->target;
+ rcu_read_unlock();
+
+ if (has_target)
+ __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
lock_policy_rwsem_write(sibling);
@@ -877,8 +882,10 @@
unlock_policy_rwsem_write(sibling);
- __cpufreq_governor(policy, CPUFREQ_GOV_START);
- __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+ if (has_target) {
+ __cpufreq_governor(policy, CPUFREQ_GOV_START);
+ __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+ }
ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
if (ret) {
@@ -1146,7 +1153,8 @@
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
- __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
+ if (has_target)
+ __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
lock_policy_rwsem_read(cpu);
kobj = &data->kobj;