cpufreq: Avoid false-positive WARN_ON()s in cpufreq_update_policy()

CPU notifications from the firmware coming in when cpufreq is
suspended cause cpufreq_update_current_freq() to return 0 which
triggers the WARN_ON() in cpufreq_update_policy() for no reason.

Avoid that by checking cpufreq_suspended before calling
cpufreq_update_current_freq().

Fixes: c9d9c929e674 (cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 9009295f5134..5617c7087d77 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2261,6 +2261,10 @@ int cpufreq_update_policy(unsigned int cpu)
          * -> ask driver for current freq and notify governors about a change
          */
         if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
+                if (cpufreq_suspended) {
+                        ret = -EAGAIN;
+                        goto unlock;
+                }
                 new_policy.cur = cpufreq_update_current_freq(policy);
                 if (WARN_ON(!new_policy.cur)) {
                         ret = -EIO;