cpufreq: Acquire the lock in cpufreq_policy_restore() for reading

In cpufreq_policy_restore() before system suspend policy is read from
percpu's cpufreq_cpu_data_fallback.  It's a read operation rather
than a write one, so take the lock for reading in there.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lan Tianyu 2013-09-11 15:05:05 +08:00 committed by Rafael J. Wysocki
parent cb38ed5cf1
commit 44871c9c7f

View file

@ -906,11 +906,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
struct cpufreq_policy *policy;
unsigned long flags;
write_lock_irqsave(&cpufreq_driver_lock, flags);
read_lock_irqsave(&cpufreq_driver_lock, flags);
policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
return policy;
}