Merge branch 'pm-opp'
* pm-opp:
PM / OPP: take RCU lock in dev_pm_opp_get_opp_count
PM / OPP: fix warning in of_free_opp_table()
PM / OPP: add some lockdep annotations
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index d24dd614a..106c693 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -108,6 +108,14 @@
/* Lock to allow exclusive modification to the device and opp lists */
static DEFINE_MUTEX(dev_opp_list_lock);
+#define opp_rcu_lockdep_assert() \
+do { \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
+ lockdep_is_held(&dev_opp_list_lock), \
+ "Missing rcu_read_lock() or " \
+ "dev_opp_list_lock protection"); \
+} while (0)
+
/**
* find_device_opp() - find device_opp struct using device pointer
* @dev: device pointer used to lookup device OPPs
@@ -208,9 +216,7 @@
* This function returns the number of available opps if there are any,
* else returns 0 if none or the corresponding error value.
*
- * Locking: This function must be called under rcu_read_lock(). This function
- * internally references two RCU protected structures: device_opp and opp which
- * are safe as long as we are under a common RCU locked section.
+ * Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_get_opp_count(struct device *dev)
{
@@ -218,11 +224,14 @@
struct dev_pm_opp *temp_opp;
int count = 0;
+ rcu_read_lock();
+
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
- int r = PTR_ERR(dev_opp);
- dev_err(dev, "%s: device OPP not found (%d)\n", __func__, r);
- return r;
+ count = PTR_ERR(dev_opp);
+ dev_err(dev, "%s: device OPP not found (%d)\n",
+ __func__, count);
+ goto out_unlock;
}
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
@@ -230,6 +239,8 @@
count++;
}
+out_unlock:
+ rcu_read_unlock();
return count;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
@@ -267,6 +278,8 @@
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+ opp_rcu_lockdep_assert();
+
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
int r = PTR_ERR(dev_opp);
@@ -313,6 +326,8 @@
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+ opp_rcu_lockdep_assert();
+
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
@@ -361,6 +376,8 @@
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+ opp_rcu_lockdep_assert();
+
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
@@ -783,9 +800,15 @@
/* Check for existing list for 'dev' */
dev_opp = find_device_opp(dev);
- if (WARN(IS_ERR(dev_opp), "%s: dev_opp: %ld\n", dev_name(dev),
- PTR_ERR(dev_opp)))
+ if (IS_ERR(dev_opp)) {
+ int error = PTR_ERR(dev_opp);
+ if (error != -ENODEV)
+ WARN(1, "%s: dev_opp: %d\n",
+ IS_ERR_OR_NULL(dev) ?
+ "Invalid device" : dev_name(dev),
+ error);
return;
+ }
/* Hold our list modification lock here */
mutex_lock(&dev_opp_list_lock);