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PM / devfreq: add locking documentation for recommended_opp

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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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Nishanth Menon 2013-01-18 19:52:34 +00:00 committed by Rafael J. Wysocki
parent 78e8eb8fea
commit bcb27549f4
1 changed files with 5 additions and 0 deletions
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5
drivers/devfreq/devfreq.c
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@ -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)