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path: root/drivers/cpufreq/cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c32
1 files changed, 23 insertions, 9 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 44db4f59c4cc..f6f8d7f450e7 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -576,17 +576,26 @@ unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
if (latency) {
+ unsigned int max_delay_us = 2 * MSEC_PER_SEC;
+
+ /*
+ * If the platform already has high transition_latency, use it
+ * as-is.
+ */
+ if (latency > max_delay_us)
+ return latency;
+
/*
- * For platforms that can change the frequency very fast (< 10
+ * For platforms that can change the frequency very fast (< 2
* us), the above formula gives a decent transition delay. But
* for platforms where transition_latency is in milliseconds, it
* ends up giving unrealistic values.
*
- * Cap the default transition delay to 10 ms, which seems to be
+ * Cap the default transition delay to 2 ms, which seems to be
* a reasonable amount of time after which we should reevaluate
* the frequency.
*/
- return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
+ return min(latency * LATENCY_MULTIPLIER, max_delay_us);
}
return LATENCY_MULTIPLIER;
@@ -1571,7 +1580,8 @@ static int cpufreq_online(unsigned int cpu)
if (cpufreq_driver->ready)
cpufreq_driver->ready(policy);
- if (cpufreq_thermal_control_enabled(cpufreq_driver))
+ /* Register cpufreq cooling only for a new policy */
+ if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver))
policy->cdev = of_cpufreq_cooling_register(policy);
pr_debug("initialization complete\n");
@@ -1655,11 +1665,6 @@ static void __cpufreq_offline(unsigned int cpu, struct cpufreq_policy *policy)
else
policy->last_policy = policy->policy;
- if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
- cpufreq_cooling_unregister(policy->cdev);
- policy->cdev = NULL;
- }
-
if (has_target())
cpufreq_exit_governor(policy);
@@ -1720,6 +1725,15 @@ static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
return;
}
+ /*
+ * Unregister cpufreq cooling once all the CPUs of the policy are
+ * removed.
+ */
+ if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
+ cpufreq_cooling_unregister(policy->cdev);
+ policy->cdev = NULL;
+ }
+
/* We did light-weight exit earlier, do full tear down now */
if (cpufreq_driver->offline)
cpufreq_driver->exit(policy);