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path: root/drivers/devfreq/devfreq.c
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Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index db70cee71caa..1ba9d02381e8 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -135,6 +135,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
int lev, prev_lev, ret = 0;
unsigned long cur_time;
+ lockdep_assert_held(&devfreq->lock);
cur_time = jiffies;
/* Immediately exit if previous_freq is not initialized yet. */
@@ -481,11 +482,6 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
static void _remove_devfreq(struct devfreq *devfreq)
{
mutex_lock(&devfreq_list_lock);
- if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
- mutex_unlock(&devfreq_list_lock);
- dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
- return;
- }
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
@@ -557,6 +553,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq->dev.parent = dev;
devfreq->dev.class = devfreq_class;
devfreq->dev.release = devfreq_dev_release;
+ INIT_LIST_HEAD(&devfreq->node);
devfreq->profile = profile;
strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
devfreq->previous_freq = profile->initial_freq;
@@ -985,7 +982,7 @@ static ssize_t available_governors_show(struct device *d,
* The devfreq with immutable governor (e.g., passive) shows
* only own governor.
*/
- if (df->governor->immutable) {
+ if (df->governor && df->governor->immutable) {
count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
"%s ", df->governor_name);
/*
@@ -1170,12 +1167,17 @@ static ssize_t trans_stat_show(struct device *dev,
int i, j;
unsigned int max_state = devfreq->profile->max_state;
- if (!devfreq->stop_polling &&
- devfreq_update_status(devfreq, devfreq->previous_freq))
- return 0;
if (max_state == 0)
return sprintf(buf, "Not Supported.\n");
+ mutex_lock(&devfreq->lock);
+ if (!devfreq->stop_polling &&
+ devfreq_update_status(devfreq, devfreq->previous_freq)) {
+ mutex_unlock(&devfreq->lock);
+ return 0;
+ }
+ mutex_unlock(&devfreq->lock);
+
len = sprintf(buf, " From : To\n");
len += sprintf(buf + len, " :");
for (i = 0; i < max_state; i++)