[PATCH 5/5] cpufreq: Get rid of ->governor_enabled and its lock

Viresh Kumar
2016-02-02T10:58:04Z

Invalid state-transitions is verified by governor core now and there is
no need to replicate that in cpufreq core. Also we don't drop
policy->rwsem anymore, which makes rest of the races go away.

Simplify code a bit now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 24 ------------------------
include/linux/cpufreq.h | 1 -
2 files changed, 25 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 5f7e24567e0e..052ad1b9372c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -102,7 +102,6 @@ static LIST_HEAD(cpufreq_governor_list);
static struct cpufreq_driver *cpufreq_driver;
static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
static DEFINE_RWLOCK(cpufreq_driver_lock);
-DEFINE_MUTEX(cpufreq_governor_lock);

/* Flag to suspend/resume CPUFreq governors */
static bool cpufreq_suspended;
@@ -1963,21 +1962,6 @@ 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;
- }
-
- if (event == CPUFREQ_GOV_STOP)
- policy->governor_enabled = false;
- else if (event == CPUFREQ_GOV_START)
- policy->governor_enabled = true;
-
- mutex_unlock(&cpufreq_governor_lock);
-
ret = policy->governor->governor(policy, event);

if (!ret) {
@@ -1985,14 +1969,6 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
policy->governor->initialized++;
else if (event == CPUFREQ_GOV_POLICY_EXIT)
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/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 79b87cebaa9c..e90cf5d31e85 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -80,7 +80,6 @@ struct cpufreq_policy {
unsigned int last_policy; /* policy before unplug */
struct cpufreq_governor *governor; /* see below */
void *governor_data;
- bool governor_enabled; /* governor start/stop flag */
char last_governor[CPUFREQ_NAME_LEN]; /* last governor used */

struct work_struct update; /* if update_policy() needs to be
--
2.7.0.79.gdc08a19