3 files changed, 54 insertions, 17 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index eb37fba9b7ef..0db9e1bda322 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -826,13 +826,21 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
 	/* set up files for this cpu device */
 	drv_attr = cpufreq_driver->attr;
 	while ((drv_attr) && (*drv_attr)) {
-		sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+		ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+		if (ret)
+			goto err_out_driver_exit;
 		drv_attr++;
 	}
-	if (cpufreq_driver->get)
-		sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
-	if (cpufreq_driver->target)
-		sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+	if (cpufreq_driver->get){
+		ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
+		if (ret)
+			goto err_out_driver_exit;
+	}
+	if (cpufreq_driver->target){
+		ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+		if (ret)
+			goto err_out_driver_exit;
+	}
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu_mask(j, policy->cpus) {
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 8532bb79e5fc..e794527e4925 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -96,15 +96,25 @@ static struct dbs_tuners {
 
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
 {
-	cputime64_t retval;
+	cputime64_t idle_time;
+	cputime64_t cur_jiffies;
+	cputime64_t busy_time;
 
-	retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
-			kstat_cpu(cpu).cpustat.iowait);
+	cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
+	busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
+			kstat_cpu(cpu).cpustat.system);
 
-	if (dbs_tuners_ins.ignore_nice)
-		retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
+	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
+	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
+	busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
 
-	return retval;
+	if (!dbs_tuners_ins.ignore_nice) {
+		busy_time = cputime64_add(busy_time,
+				kstat_cpu(cpu).cpustat.nice);
+	}
+
+	idle_time = cputime64_sub(cur_jiffies, busy_time);
+	return idle_time;
 }
 
 /*
@@ -325,7 +335,7 @@ static struct attribute_group dbs_attr_group = {
 static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 {
 	unsigned int idle_ticks, total_ticks;
-	unsigned int load;
+	unsigned int load = 0;
 	cputime64_t cur_jiffies;
 
 	struct cpufreq_policy *policy;
@@ -339,7 +349,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 	cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
 	total_ticks = (unsigned int) cputime64_sub(cur_jiffies,
 			this_dbs_info->prev_cpu_wall);
-	this_dbs_info->prev_cpu_wall = cur_jiffies;
+	this_dbs_info->prev_cpu_wall = get_jiffies_64();
+
 	if (!total_ticks)
 		return;
 	/*
@@ -370,7 +381,8 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 		if (tmp_idle_ticks < idle_ticks)
 			idle_ticks = tmp_idle_ticks;
 	}
-	load = (100 * (total_ticks - idle_ticks)) / total_ticks;
+	if (likely(total_ticks > idle_ticks))
+		load = (100 * (total_ticks - idle_ticks)) / total_ticks;
 
 	/* Check for frequency increase */
 	if (load > dbs_tuners_ins.up_threshold) {
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index a648970338b0..51bedab6c808 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -37,6 +37,7 @@ static unsigned int	cpu_set_freq[NR_CPUS]; /* CPU freq desired by userspace */
 static unsigned int	cpu_is_managed[NR_CPUS];
 
 static DEFINE_MUTEX	(userspace_mutex);
+static int cpus_using_userspace_governor;
 
 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg)
 
@@ -47,7 +48,11 @@ userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
 {
         struct cpufreq_freqs *freq = data;
 
-	dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n", freq->cpu, freq->new);
+	if (!cpu_is_managed[freq->cpu])
+		return 0;
+
+	dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n",
+			freq->cpu, freq->new);
 	cpu_cur_freq[freq->cpu] = freq->new;
 
         return 0;
@@ -142,6 +147,13 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
 		if (rc)
 			goto start_out;
 
+		if (cpus_using_userspace_governor == 0) {
+			cpufreq_register_notifier(
+					&userspace_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+		}
+		cpus_using_userspace_governor++;
+
 		cpu_is_managed[cpu] = 1;
 		cpu_min_freq[cpu] = policy->min;
 		cpu_max_freq[cpu] = policy->max;
@@ -153,6 +165,13 @@ start_out:
 		break;
 	case CPUFREQ_GOV_STOP:
 		mutex_lock(&userspace_mutex);
+		cpus_using_userspace_governor--;
+		if (cpus_using_userspace_governor == 0) {
+			cpufreq_unregister_notifier(
+					&userspace_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+		}
+
 		cpu_is_managed[cpu] = 0;
 		cpu_min_freq[cpu] = 0;
 		cpu_max_freq[cpu] = 0;
@@ -198,7 +217,6 @@ EXPORT_SYMBOL(cpufreq_gov_userspace);
 
 static int __init cpufreq_gov_userspace_init(void)
 {
-	cpufreq_register_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 	return cpufreq_register_governor(&cpufreq_gov_userspace);
 }
 
@@ -206,7 +224,6 @@ static int __init cpufreq_gov_userspace_init(void)
 static void __exit cpufreq_gov_userspace_exit(void)
 {
 	cpufreq_unregister_governor(&cpufreq_gov_userspace);
-        cpufreq_unregister_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 }