Commit 0a300767 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpufreq: Introduce cpufreq_start_governor() 



Starting a governor in cpufreq always follows the same pattern
involving two calls to cpufreq_governor(), one with the event
argument set to CPUFREQ_GOV_START and one with that argument set to
CPUFREQ_GOV_LIMITS.

Introduce cpufreq_start_governor() that will carry out those two
operations and make all places where governors are started use it.

That slightly modifies the behavior of cpufreq_set_policy() which
now also will go back to the old governor if the second call to
cpufreq_governor() (the one with event equal to CPUFREQ_GOV_LIMITS)
fails, but that really is how it should work in the first place.

Also cpufreq_resume() will now pring an error message if the
CPUFREQ_GOV_LIMITS call to cpufreq_governor() fails, but that
makes it follow cpufreq_add_policy_cpu() and cpufreq_offline()
in that respect.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 1b028984

drivers/cpufreq/cpufreq.c

+22 −22
Original line number Diff line number Diff line
@@ -76,6 +76,7 @@ static inline bool has_target(void) 
/* internal prototypes */

static int cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);

static unsigned int __cpufreq_get(struct cpufreq_policy *policy);

static int cpufreq_start_governor(struct cpufreq_policy *policy);



/**

 * Two notifier lists: the "policy" list is involved in the
@@ -964,10 +965,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp 
	cpumask_set_cpu(cpu, policy->cpus);



	if (has_target()) {

		ret = cpufreq_governor(policy, CPUFREQ_GOV_START);

		if (!ret)

			ret = cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);



		ret = cpufreq_start_governor(policy);

		if (ret)

			pr_err("%s: Failed to start governor\n", __func__);

	}
@@ -1308,10 +1306,7 @@ static void cpufreq_offline(unsigned int cpu) 
	/* Start governor again for active policy */

	if (!policy_is_inactive(policy)) {

		if (has_target()) {

			ret = cpufreq_governor(policy, CPUFREQ_GOV_START);

			if (!ret)

				ret = cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);



			ret = cpufreq_start_governor(policy);

			if (ret)

				pr_err("%s: Failed to start governor\n", __func__);

		}
@@ -1591,9 +1586,7 @@ void cpufreq_resume(void) 
				policy);

		} else {

			down_write(&policy->rwsem);

			ret = cpufreq_governor(policy, CPUFREQ_GOV_START);

			if (!ret)

				cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);

			ret = cpufreq_start_governor(policy);

			up_write(&policy->rwsem);



			if (ret)
@@ -1935,6 +1928,14 @@ static int cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) 
	return ret;

}



static int cpufreq_start_governor(struct cpufreq_policy *policy)

{

	int ret;



	ret = cpufreq_governor(policy, CPUFREQ_GOV_START);

	return ret ? ret : cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);

}



int cpufreq_register_governor(struct cpufreq_governor *governor)

{

	int err;
@@ -2071,8 +2072,10 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
		return cpufreq_driver->setpolicy(new_policy);

	}



	if (new_policy->governor == policy->governor)

		goto out;

	if (new_policy->governor == policy->governor) {

		pr_debug("cpufreq: governor limits update\n");

		return cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);

	}



	pr_debug("governor switch\n");
@@ -2100,10 +2103,11 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
	policy->governor = new_policy->governor;

	ret = cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);

	if (!ret) {

		ret = cpufreq_governor(policy, CPUFREQ_GOV_START);

		if (!ret)

			goto out;



		ret = cpufreq_start_governor(policy);

		if (!ret) {

			pr_debug("cpufreq: governor change\n");

			return 0;

		}

		cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);

	}
@@ -2114,14 +2118,10 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
		if (cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT))

			policy->governor = NULL;

		else

			cpufreq_governor(policy, CPUFREQ_GOV_START);

			cpufreq_start_governor(policy);

	}



	return ret;



 out:

	pr_debug("governor: change or update limits\n");

	return cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);

}



/**

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