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Commit bcb27549 authored by Nishanth Menon's avatar Nishanth Menon Committed by Rafael J. Wysocki
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PM / devfreq: add locking documentation for recommended_opp 



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: default avatarNishanth Menon <nm@ti.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 78e8eb8f

drivers/devfreq/devfreq.c

+5 −0
Original line number Diff line number Diff line
@@ -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)