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Subject[PATCH 3/4] PM / devfreq: add locking documentation for recommended_opp
Date
OPP pointers are protected by RCU locks, the pointer validity is
permissible only under the section of rcu_read_lock to rcu_read_unlock

Add documentation to the effect.

Signed-off-by: Nishanth Menon <nm@ti.com>
---
drivers/devfreq/devfreq.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 53766f3..3b36797 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -994,6 +994,11 @@ module_exit(devfreq_exit);
* @freq: The frequency given to target function
* @flags: Flags handed from devfreq framework.
*
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
u32 flags)
--
1.7.9.5


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