On Sun, Apr 10, 2016 at 5:16 AM, Viresh Kumar <viresh.ku...@linaro.org> wrote:
> On 08-04-16, 23:54, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>> Subject: [PATCH] cpufreq: Skip all governor-related actions for
>> cpufreq_suspended set
>>
>> Since governor operations are generally skipped if cpufreq_suspended
>> is set, do nothing at all in cpufreq_start_governor() 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.
>>
>> The change here prevents problems from happening for this reason.
>>
>> Fixes: 3bbf8fe3ae08 (cpufreq: Always update current frequency before startig
>> governor)
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>> Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
>> ---
>> drivers/cpufreq/cpufreq.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> Index: linux-pm/drivers/cpufreq/cpufreq.c
>> ===================================================================
>> --- linux-pm.orig/drivers/cpufreq/cpufreq.c
>> +++ linux-pm/drivers/cpufreq/cpufreq.c
>> @@ -2053,6 +2053,9 @@ static int cpufreq_start_governor(struct
>> {
>> int ret;
>>
>> + if (cpufreq_suspended)
>> + return 0;
>> +
>> if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
>> cpufreq_update_current_freq(policy);
>
> Since we no longer have the same check in cpufreq_exit_governor(),
> what about moving it to cpufreq_update_current_freq() instead? That's
> all we are trying to protect here anyway, as cpufreq_governor() is
> already protected.
That can be done too.
