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PM / OPP: Add opp_rcu_lockdep_assert() to _find_device_opp() 

_find_device_opp() should be called with rcu-read lock or
dev_opp_list_lock held. Add the opp_rcu_lockdep_assert() check to make
sure caller have taken appropriate locks.

Fix comment over the routine as well.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2015-11-05 14:21:21 +05:30 committed by Rafael J. Wysocki
parent 4a3a1353a8
commit 0597e81850
1 changed files with 7 additions and 3 deletions
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10
drivers/base/power/opp/core.c
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@ -81,14 +81,18 @@ static struct device_opp *_managed_opp(const struct device_node *np)
* Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or * Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or
* -EINVAL based on type of error. * -EINVAL based on type of error.
* *
* Locking: This function must be called under rcu_read_lock(). device_opp * Locking: For readers, this function must be called under rcu_read_lock().
* is a RCU protected pointer. This means that device_opp is valid as long * device_opp is a RCU protected pointer, which means that device_opp is valid
* as we are under RCU lock. * as long as we are under RCU lock.
*
* For Writers, this function must be called with dev_opp_list_lock held.
*/ */
struct device_opp *_find_device_opp(struct device *dev) struct device_opp *_find_device_opp(struct device *dev)
{ {
struct device_opp *dev_opp; struct device_opp *dev_opp;
opp_rcu_lockdep_assert();
if (IS_ERR_OR_NULL(dev)) { if (IS_ERR_OR_NULL(dev)) {
pr_err("%s: Invalid parameters\n", __func__); pr_err("%s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL); return ERR_PTR(-EINVAL);