cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set

Since governor operations are generally skipped if cpufreq_suspended
is set, cpufreq_start_governor() should do nothing in that case.

That function is called in the cpufreq_online() path, and may also
be called from cpufreq_offline() in some cases, which are invoked
by the nonboot CPUs disabing/enabling code during system suspend
to RAM and resume.  That happens when all devices have been
suspended, so if the cpufreq driver relies on things like I2C to
get the current frequency, it may not be ready to do that then.

To prevent problems from happening for this reason, make
cpufreq_update_current_freq(), which is the only function invoked
by cpufreq_start_governor() that doesn't check cpufreq_suspended
already, return 0 upfront if cpufreq_suspended is set.

Fixes: 3bbf8fe3ae08 (cpufreq: Always update current frequency before startig governor)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b87596b591b3ca9fdf332884700e5a3cc96ebf10..e93405f0eac46565d18c25873d1113c3a1aa65fd 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1491,6 +1491,9 @@ static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy)
 {
        unsigned int new_freq;
 
+       if (cpufreq_suspended)
+               return 0;
+
        new_freq = cpufreq_driver->get(policy->cpu);
        if (!new_freq)
                return 0;