We used to drop policy->rwsem just before calling __cpufreq_governor()
in some cases earlier and so it was possible that __cpufreq_governor()
runs concurrently via separate threads.
In order to guarantee valid state transitions for governors,
'governor_enabled' was required to be protected using some locking and
we created cpufreq_governor_lock for that.
But now, __cpufreq_governor() is always called from within policy->rwsem
held and so 'governor_enabled' is protected against races even without
cpufreq_governor_lock.
Get rid of the extra lock now.
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
drivers/cpufreq/cpufreq.c | 8 --------
drivers/cpufreq/cpufreq_governor.h | 1 -
2 files changed, 9 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 51fb47cd38a0..745da90d7b38 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -146,8 +146,6 @@ void cpufreq_update_util(u64 time, unsigned long util,
unsigned long max)
rcu_read_unlock();
}
-DEFINE_MUTEX(cpufreq_governor_lock);
-
/* Flag to suspend/resume CPUFreq governors */
static bool cpufreq_suspended;
@@ -2014,11 +2012,9 @@ static int __cpufreq_governor(struct cpufreq_policy
*policy,
pr_debug("%s: for CPU %u, event %u\n", __func__, policy->cpu, event);
- mutex_lock(&cpufreq_governor_lock);
if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
|| (!policy->governor_enabled
&& (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
- mutex_unlock(&cpufreq_governor_lock);
return -EBUSY;
}
@@ -2027,8 +2023,6 @@ static int __cpufreq_governor(struct cpufreq_policy
*policy,
else if (event == CPUFREQ_GOV_START)
policy->governor_enabled = true;
- mutex_unlock(&cpufreq_governor_lock);
-
ret = policy->governor->governor(policy, event);
if (!ret) {
@@ -2038,12 +2032,10 @@ static int __cpufreq_governor(struct cpufreq_policy
*policy,
policy->governor->initialized--;
} else {
/* Restore original values */
- mutex_lock(&cpufreq_governor_lock);
if (event == CPUFREQ_GOV_STOP)
policy->governor_enabled = true;
else if (event == CPUFREQ_GOV_START)
policy->governor_enabled = false;
- mutex_unlock(&cpufreq_governor_lock);
}
if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
diff --git a/drivers/cpufreq/cpufreq_governor.h
b/drivers/cpufreq/cpufreq_governor.h
index f164437f235e..886578b5a4fd 100644
--- a/drivers/cpufreq/cpufreq_governor.h
+++ b/drivers/cpufreq/cpufreq_governor.h
@@ -228,7 +228,6 @@ static inline int delay_for_sampling_rate(unsigned int
sampling_rate)
}
extern struct mutex dbs_data_mutex;
-extern struct mutex cpufreq_governor_lock;
void dbs_check_cpu(struct cpufreq_policy *policy);
int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event);
void od_register_powersave_bias_handler(unsigned int (*f)
--
2.7.1.370.gb2aa7f8
