Commit 4bc384ae authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: propagate errors returned from __cpufreq_governor() 



Return codes aren't honored properly in cpufreq_set_policy(). This can
lead to two problems:
- wrong errors propagated to sysfs
- we try to do next state-change even if the previous one failed

cpufreq_governor_dbs() now returns proper errors on all invalid
state-transition requests and this code should honor that.

Reviewed-and-tested-by: default avatarPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 871ef3b5

drivers/cpufreq/cpufreq.c

+24 −7
Original line number Diff line number Diff line
@@ -2295,16 +2295,31 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
	old_gov = policy->governor;

	/* end old governor */

	if (old_gov) {

		__cpufreq_governor(policy, CPUFREQ_GOV_STOP);

		ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);

		if (ret) {

			/* This can happen due to race with other operations */

			pr_debug("%s: Failed to Stop Governor: %s (%d)\n",

				 __func__, old_gov->name, ret);

			return ret;

		}



		up_write(&policy->rwsem);

		__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);

		ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);

		down_write(&policy->rwsem);



		if (ret) {

			pr_err("%s: Failed to Exit Governor: %s (%d)\n",

			       __func__, old_gov->name, ret);

			return ret;

		}

	}



	/* start new governor */

	policy->governor = new_policy->governor;

	if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {

		if (!__cpufreq_governor(policy, CPUFREQ_GOV_START))

	ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);

	if (!ret) {

		ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);

		if (!ret)

			goto out;



		up_write(&policy->rwsem);
@@ -2316,11 +2331,13 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
	pr_debug("starting governor %s failed\n", policy->governor->name);

	if (old_gov) {

		policy->governor = old_gov;

		__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);

		if (__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT))

			policy->governor = NULL;

		else

			__cpufreq_governor(policy, CPUFREQ_GOV_START);

	}



	return -EINVAL;

	return ret;



 out:

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

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