On 10 April 2016 at 09:38, Rafael J. Wysocki <r...@rjwysocki.net> wrote:
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>
> 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.wyso...@intel.com>
> ---
> drivers/cpufreq/cpufreq.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> Index: linux-pm/drivers/cpufreq/cpufreq.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/cpufreq.c
> +++ linux-pm/drivers/cpufreq/cpufreq.c
> @@ -1565,6 +1565,9 @@ static unsigned int cpufreq_update_curre
> {
> unsigned int new_freq;
>
> + if (cpufreq_suspended)
> + return 0;
> +
> new_freq = cpufreq_driver->get(policy->cpu);
> if (!new_freq)
> return 0;
Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
