Merge branch 'master'

4 files changed, 33 insertions, 32 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8d328186f77..bc1088d9b37 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -364,10 +364,12 @@ static ssize_t store_##file_name					\
 	if (ret != 1)							\
 		return -EINVAL;						\
 									\
+	lock_cpu_hotplug();						\
 	mutex_lock(&policy->lock);					\
 	ret = __cpufreq_set_policy(policy, &new_policy);		\
 	policy->user_policy.object = policy->object;			\
 	mutex_unlock(&policy->lock);					\
+	unlock_cpu_hotplug();						\
 									\
 	return ret ? ret : count;					\
 }
@@ -1197,20 +1199,18 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier);
  *********************************************************************/
 
 
+/* Must be called with lock_cpu_hotplug held */
 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int target_freq,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
 
-	lock_cpu_hotplug();
 	dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
 		target_freq, relation);
 	if (cpu_online(policy->cpu) && cpufreq_driver->target)
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 
-	unlock_cpu_hotplug();
-
 	return retval;
 }
 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
@@ -1225,17 +1225,23 @@ int cpufreq_driver_target(struct cpufreq_policy *policy,
 	if (!policy)
 		return -EINVAL;
 
+	lock_cpu_hotplug();
 	mutex_lock(&policy->lock);
 
 	ret = __cpufreq_driver_target(policy, target_freq, relation);
 
 	mutex_unlock(&policy->lock);
+	unlock_cpu_hotplug();
 
 	cpufreq_cpu_put(policy);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
 
+/*
+ * Locking: Must be called with the lock_cpu_hotplug() lock held
+ * when "event" is CPUFREQ_GOV_LIMITS
+ */
 
 static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
 {
@@ -1257,24 +1263,6 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
 }
 
 
-int cpufreq_governor(unsigned int cpu, unsigned int event)
-{
-	int ret = 0;
-	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
-
-	if (!policy)
-		return -EINVAL;
-
-	mutex_lock(&policy->lock);
-	ret = __cpufreq_governor(policy, event);
-	mutex_unlock(&policy->lock);
-
-	cpufreq_cpu_put(policy);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(cpufreq_governor);
-
-
 int cpufreq_register_governor(struct cpufreq_governor *governor)
 {
 	struct cpufreq_governor *t;
@@ -1342,6 +1330,9 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
 EXPORT_SYMBOL(cpufreq_get_policy);
 
 
+/*
+ * Locking: Must be called with the lock_cpu_hotplug() lock held
+ */
 static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
 {
 	int ret = 0;
@@ -1436,6 +1427,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
 	if (!data)
 		return -EINVAL;
 
+	lock_cpu_hotplug();
+
 	/* lock this CPU */
 	mutex_lock(&data->lock);
 
@@ -1446,6 +1439,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
 	data->user_policy.governor = data->governor;
 
 	mutex_unlock(&data->lock);
+
+	unlock_cpu_hotplug();
 	cpufreq_cpu_put(data);
 
 	return ret;
@@ -1469,6 +1464,7 @@ int cpufreq_update_policy(unsigned int cpu)
 	if (!data)
 		return -ENODEV;
 
+	lock_cpu_hotplug();
 	mutex_lock(&data->lock);
 
 	dprintk("updating policy for CPU %u\n", cpu);
@@ -1494,7 +1490,7 @@ int cpufreq_update_policy(unsigned int cpu)
 	ret = __cpufreq_set_policy(data, &policy);
 
 	mutex_unlock(&data->lock);
-
+	unlock_cpu_hotplug();
 	cpufreq_cpu_put(data);
 	return ret;
 }
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index b3ebc8f0197..c4c578defab 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -525,7 +525,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		break;
 
 	case CPUFREQ_GOV_LIMITS:
-		lock_cpu_hotplug();
 		mutex_lock(&dbs_mutex);
 		if (policy->max < this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(
@@ -536,7 +535,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 					this_dbs_info->cur_policy,
 				       	policy->min, CPUFREQ_RELATION_L);
 		mutex_unlock(&dbs_mutex);
-		unlock_cpu_hotplug();
 		break;
 	}
 	return 0;
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 87299924e73..52cf1f02182 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -239,6 +239,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 	total_ticks = (unsigned int) cputime64_sub(cur_jiffies,
 			this_dbs_info->prev_cpu_wall);
 	this_dbs_info->prev_cpu_wall = cur_jiffies;
+	if (!total_ticks)
+		return;
 	/*
 	 * Every sampling_rate, we check, if current idle time is less
 	 * than 20% (default), then we try to increase frequency
@@ -304,7 +306,12 @@ static void do_dbs_timer(void *data)
 	unsigned int cpu = smp_processor_id();
 	struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
 
+	if (!dbs_info->enable)
+		return;
+
+	lock_cpu_hotplug();
 	dbs_check_cpu(dbs_info);
+	unlock_cpu_hotplug();
 	queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work,
 			usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
 }
@@ -319,11 +326,11 @@ static inline void dbs_timer_init(unsigned int cpu)
 	return;
 }
 
-static inline void dbs_timer_exit(unsigned int cpu)
+static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
 {
-	struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
-
-	cancel_rearming_delayed_workqueue(kondemand_wq, &dbs_info->work);
+	dbs_info->enable = 0;
+	cancel_delayed_work(&dbs_info->work);
+	flush_workqueue(kondemand_wq);
 }
 
 static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
@@ -396,8 +403,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 	case CPUFREQ_GOV_STOP:
 		mutex_lock(&dbs_mutex);
-		dbs_timer_exit(policy->cpu);
-		this_dbs_info->enable = 0;
+		dbs_timer_exit(this_dbs_info);
 		sysfs_remove_group(&policy->kobj, &dbs_attr_group);
 		dbs_enable--;
 		if (dbs_enable == 0)
@@ -408,7 +414,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		break;
 
 	case CPUFREQ_GOV_LIMITS:
-		lock_cpu_hotplug();
 		mutex_lock(&dbs_mutex);
 		if (policy->max < this_dbs_info->cur_policy->cur)
 			__cpufreq_driver_target(this_dbs_info->cur_policy,
@@ -419,7 +424,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			                        policy->min,
 			                        CPUFREQ_RELATION_L);
 		mutex_unlock(&dbs_mutex);
-		unlock_cpu_hotplug();
 		break;
 	}
 	return 0;
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index 44ae5e5b94c..a06c204589c 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -18,6 +18,7 @@
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/cpufreq.h>
+#include <linux/cpu.h>
 #include <linux/types.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
@@ -70,6 +71,7 @@ static int cpufreq_set(unsigned int freq, struct cpufreq_policy *policy)
 
 	dprintk("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
 
+	lock_cpu_hotplug();
 	mutex_lock(&userspace_mutex);
 	if (!cpu_is_managed[policy->cpu])
 		goto err;
@@ -92,6 +94,7 @@ static int cpufreq_set(unsigned int freq, struct cpufreq_policy *policy)
 
  err:
 	mutex_unlock(&userspace_mutex);
+	unlock_cpu_hotplug();
 	return ret;
 }