1 files changed, 17 insertions, 4 deletions

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index c70ebf53415..7d1952c5cb1 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -34,7 +34,7 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/cpufreq_interactive.h>
 
-static atomic_t active_count = ATOMIC_INIT(0);
+static int active_count;
 
 struct cpufreq_interactive_cpuinfo {
         struct timer_list cpu_timer;
@@ -60,6 +60,7 @@ static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
 static struct task_struct *speedchange_task;
 static cpumask_t speedchange_cpumask;
 static spinlock_t speedchange_cpumask_lock;
+static struct mutex gov_lock;
 
 /* Hi speed to bump to from lo speed when load burst (default max) */
 static unsigned int hispeed_freq;
@@ -913,6 +914,8 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                 if (!cpu_online(policy->cpu))
                         return -EINVAL;
 
+                mutex_lock(&gov_lock);
+
                 freq_table =
                         cpufreq_frequency_get_table(policy->cpu);
                 if (!hispeed_freq)
@@ -947,20 +950,26 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                  * Do not register the idle hook and create sysfs
                  * entries if we have already done so.
                  */
-                if (atomic_inc_return(&active_count) > 1)
+                if (++active_count > 1) {
+                        mutex_unlock(&gov_lock);
                         return 0;
+                }
 
                 rc = sysfs_create_group(cpufreq_global_kobject,
                                 &interactive_attr_group);
-                if (rc)
+                if (rc) {
+                        mutex_unlock(&gov_lock);
                         return rc;
+                }
 
                 idle_notifier_register(&cpufreq_interactive_idle_nb);
                 cpufreq_register_notifier(
                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
+                mutex_unlock(&gov_lock);
                 break;
 
         case CPUFREQ_GOV_STOP:
+                mutex_lock(&gov_lock);
                 for_each_cpu(j, policy->cpus) {
                         pcpu = &per_cpu(cpuinfo, j);
                         down_write(&pcpu->enable_sem);
@@ -970,14 +979,17 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                         up_write(&pcpu->enable_sem);
                 }
 
-                if (atomic_dec_return(&active_count) > 0)
+                if (--active_count > 0) {
+                        mutex_unlock(&gov_lock);
                         return 0;
+                }
 
                 cpufreq_unregister_notifier(
                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
                 sysfs_remove_group(cpufreq_global_kobject,
                                 &interactive_attr_group);
+                mutex_unlock(&gov_lock);
 
                 break;
 
@@ -1017,6 +1029,7 @@ static int __init cpufreq_interactive_init(void)
 
         spin_lock_init(&target_loads_lock);
         spin_lock_init(&speedchange_cpumask_lock);
+        mutex_init(&gov_lock);
         speedchange_task =
                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
                                "cfinteractive");