Commit 70a59fde authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update() 



On some occasions cpufreq_verify_current_freq() schedules a work whose
callback is handle_update(), which further calls cpufreq_update_policy()
which may end up calling cpufreq_verify_current_freq() again.

On the other hand, when cpufreq_update_policy() is called from
handle_update(), the pointer to the cpufreq policy is already
available, but cpufreq_cpu_acquire() is still called to get it in
cpufreq_update_policy(), which should be avoided as well.

To fix these issues, create a new helper, refresh_frequency_limits(),
and make both handle_update() call it cpufreq_update_policy().

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ]
[ rjw: Changelog ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 5980752e

drivers/cpufreq/cpufreq.c

+16 −10
Original line number Diff line number Diff line
@@ -1115,13 +1115,25 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp 
	return ret;

}



static void refresh_frequency_limits(struct cpufreq_policy *policy)

{

	struct cpufreq_policy new_policy = *policy;



	pr_debug("updating policy for CPU %u\n", policy->cpu);



	new_policy.min = policy->user_policy.min;

	new_policy.max = policy->user_policy.max;



	cpufreq_set_policy(policy, &new_policy);

}



static void handle_update(struct work_struct *work)

{

	struct cpufreq_policy *policy =

		container_of(work, struct cpufreq_policy, update);

	unsigned int cpu = policy->cpu;

	pr_debug("handle_update for cpu %u called\n", cpu);

	cpufreq_update_policy(cpu);



	pr_debug("handle_update for cpu %u called\n", policy->cpu);

	refresh_frequency_limits(policy);

}



static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
@@ -2376,7 +2388,6 @@ int cpufreq_set_policy(struct cpufreq_policy *policy, 
void cpufreq_update_policy(unsigned int cpu)

{

	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);

	struct cpufreq_policy new_policy;



	if (!policy)

		return;
@@ -2389,12 +2400,7 @@ void cpufreq_update_policy(unsigned int cpu) 
	    (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))

		goto unlock;



	pr_debug("updating policy for CPU %u\n", cpu);

	memcpy(&new_policy, policy, sizeof(*policy));

	new_policy.min = policy->user_policy.min;

	new_policy.max = policy->user_policy.max;



	cpufreq_set_policy(policy, &new_policy);

	refresh_frequency_limits(policy);



unlock:

	cpufreq_cpu_release(policy);

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