Commit 44871c9c authored Sep 11, 2013 by Lan Tianyu Committed by Rafael J. Wysocki Sep 11, 2013

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>

parent cb38ed5c

drivers/cpufreq/cpufreq.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}