linux-kernel - Re: [PATCH] cpufreq: governors: Remove duplicate check of target freq in supported range

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Message-ID: <521CC9B8.2020801@semaphore.gr>
Date:	Tue, 27 Aug 2013 18:46:00 +0300
From:	Stratos Karafotis <stratosk@...aphore.gr>
To:	Viresh Kumar <viresh.kumar@...aro.org>
CC:	"Rafael J. Wysocki" <rjw@...k.pl>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] cpufreq: governors: Remove duplicate check of target
 freq in supported range

On 08/27/2013 08:57 AM, Viresh Kumar wrote:
> On 27 August 2013 00:07, Stratos Karafotis <stratosk@...aphore.gr> wrote:
>>   drivers/cpufreq/cpufreq_conservative.c | 4 ----
> 
> Get rid of few more checks..
> 
> /* if we are already at full speed then break out early */
> if (dbs_info->requested_freq == policy->max)
> return;
> 
> 
> /*
> * if we cannot reduce the frequency anymore, break out early
> */
> if (policy->cur == policy->min)
> return;
> 

I think we should keep these checks because:

1) They shorten the execution code (there is no unnecessary call of
__cpufreq_driver_target)
2) In case my patch will be accepted, we need them to avoid continuously
increase of dbs_info->requested_freq.With my patch the requested_freq
can temporarily overcome policy->min and policy->max. __cpufreq_driver_target
will select the correct frequency (within policy->min and policy->max).
Then, dbs_cpufreq_notifier will adjust requested_freq.

I hope the logic in 2) to be acceptable.

Thanks,
Stratos
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