[PATCH 3/3] cpufreq: Always update current frequency before startig governor

From: Rafael J. Wysocki
Date: Mon Mar 21 2016 - 10:46:16 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Make policy->cur match the current frequency returned by the driver's
->get() callback before starting the governor in case they went out of
sync in the meantime and drop the piece of code attempting to
resync policy->cur with the real frequency of the boot CPU from
cpufreq_resume() as it serves no purpose any more (and it's racy and
super-ugly anyway).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -1680,17 +1680,6 @@ void cpufreq_resume(void)
__func__, policy);
}
}
-
- /*
- * schedule call cpufreq_update_policy() for first-online CPU, as that
- * wouldn't be hotplugged-out on suspend. It will verify that the
- * current freq is in sync with what we believe it to be.
- */
- policy = cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask));
- if (WARN_ON(!policy))
- return;
-
- schedule_work(&policy->update);
}

/**
@@ -2062,6 +2051,9 @@ static int cpufreq_start_governor(struct
{
int ret;

+ if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
+ cpufreq_update_current_freq(policy);
+
ret = cpufreq_governor(policy, CPUFREQ_GOV_START);
return ret ? ret : cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
}