linux-kernel - Re: [PATCH] cpufreq: Call cpufreq_disable_fast_switch() in sugov

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Message-ID: <20160408061929.GG9674@vireshk-i7>
Date:	Fri, 8 Apr 2016 11:49:29 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Linux PM list <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: Re: [PATCH] cpufreq: Call cpufreq_disable_fast_switch() in
 sugov_exit()

On 07-04-16, 23:38, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Due to differences in the cpufreq core's handling of runtime CPU
> offline and nonboot CPUs disabling during system suspend-to-RAM,
> fast frequency switching gets disabled after a suspend-to-RAM and
> resume cycle on all of the nonboot CPUs.
> 
> To prevent that from happening, move the invocation of
> cpufreq_disable_fast_switch() from cpufreq_exit_governor() to
> sugov_exit(), as the schedutil governor is the only user of fast
> frequency switching today anyway.
> 
> That simply prevents cpufreq_disable_fast_switch() from being called
> without invoking the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT
> event (which happens during system suspend now).
> 
> Fixes: b7898fda5bc7 (cpufreq: Support for fast frequency switching)
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh