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From: Viresh Kumar <viresh.kumar@linaro.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux PM list <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: Re: [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume()
Date: Thu, 17 Mar 2016 13:30:00 +0700	[thread overview]
Message-ID: <20160317063000.GC14898@vireshk-mac-ubuntu> (raw)
In-Reply-To: <CAJZ5v0gdnaw_BwW6ugT102YA+-Pb8O578Anf1b2vetEXsvCgzw@mail.gmail.com>

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

      reply	other threads:[~2016-03-17  6:30 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-12  2:05 [PATCH] cpufreq: Do not schedule policy update work in cpufreq_resume() Rafael J. Wysocki
2016-03-15  6:10 ` Viresh Kumar
2016-03-15 12:11   ` Rafael J. Wysocki
2016-03-16  0:51     ` Rafael J. Wysocki
2016-03-16  4:52       ` Viresh Kumar
2016-03-16 12:29         ` Rafael J. Wysocki
2016-03-17  6:44           ` Viresh Kumar
2016-03-16  4:47     ` Viresh Kumar
2016-03-16 13:12       ` Rafael J. Wysocki
2016-03-17  6:30         ` Viresh Kumar [this message]

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