cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Sun, 10 Apr 2016 03:59:33 +0000 (05:59 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Mon, 18 Apr 2016 21:47:42 +0000 (23:47 +0200)
commitc9d9c929e6741118776eb0f385339d3c2b84d5f8
treefd68bd13b665092f5f0308b516102e7a15be61ae
parentffb810563c0c049872a504978e06c8892104fb6c
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>
drivers/cpufreq/cpufreq.c