cpufreq: Detect spurious invocations of update_policy_cpu()

The function update_policy_cpu() is expected to be called when the policy->cpu
of a cpufreq policy is to be changed: ie., the new CPU nominated to become the
policy->cpu is different from the old one.

Print a warning if it is invoked with new_cpu == old_cpu, since such an
invocation might hint at a faulty logic in the caller.

Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-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>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f0897c7..ec391d7 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -969,7 +969,7 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
 
 static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
 {
-       if (cpu == policy->cpu)
+       if (WARN_ON(cpu == policy->cpu))
                return;
 
        /*