Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume()

From	Viresh Kumar <viresh.kumar@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume()
Date	2016-03-17 07:40 +0100
Message-ID	<rdzLc-3CY-9@gated-at.bofh.it> (permalink)
References	<rbHa9-7jY-3@gated-at.bofh.it> <rcQuJ-6Fh-1@gated-at.bofh.it> <rcW78-1Xi-5@gated-at.bofh.it> <rdbzd-3NJ-11@gated-at.bofh.it> <rdjwK-YM-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 16-03-16, 14:12, Rafael J. Wysocki wrote:
> No, it won't.  This might be applicable to other governors, but not to
> "performance" (look at what it does on _START instead of just
> guessing).
> 
> > So, your patch break things for sure.
> 
> I'm not actually sure it breaks anything.
> 
> Theoretically, it may, but practically?  Is there any system out there
> where it makes any difference?

AFAIU, this patch will break currently working governors.

-> cpufreq_resume()
  -> cpufreq_governor_performance(START)
    -> __cpufreq_driver_target(target_freq = policy->max)
    //policy->cur is already set to policy->max before suspend.
        if (target_freq == policy->cur)
                return 0;

And so, the real frequency stays to 500 MHz and policy->cur contains 1 GHz.

-- 
viresh

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-03-12 03:10 +0100
  Re: [PATCH] cpufreq: Do not schedule policy update work in  cpufreq_resume() Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-15 07:20 +0100
    Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-15 13:20 +0100
      Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 02:00 +0100
        Re: [PATCH] cpufreq: Do not schedule policy update work in  cpufreq_resume() Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-16 06:00 +0100
          Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 13:30 +0100
            Re: [PATCH] cpufreq: Do not schedule policy update work in  cpufreq_resume() Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-17 07:50 +0100
      Re: [PATCH] cpufreq: Do not schedule policy update work in  cpufreq_resume() Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-16 05:50 +0100
        Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() "Rafael J. Wysocki" <rafael@kernel.org> - 2016-03-16 14:20 +0100
          Re: [PATCH] cpufreq: Do not schedule policy update work in  cpufreq_resume() Viresh Kumar <viresh.kumar@linaro.org> - 2016-03-17 07:40 +0100

csiph-web