linux-kernel - Re: [PATCH] Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition

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Message-ID: <3860863.MLaNBM27lJ@vostro.rjw.lan>
Date:	Fri, 22 Jul 2016 23:46:08 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	Andreas Herrmann <aherrmann@...e.com>,
	Jacob Tanenbaum <jtanenba@...hat.com>, stable@...r.kernel.org,
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency"

On Friday, July 22, 2016 02:28:52 PM Viresh Kumar wrote:
> On 22-07-16, 23:31, Rafael J. Wysocki wrote:
> > > cpufreq.c
> > > 
> > > 	if (policy->governor->max_transition_latency &&
> > > 	    policy->cpuinfo.transition_latency >
> > > 	    policy->governor->max_transition_latency) {
> > > 
> > > - And this check will always fail, unless max_transition_latency is zero.
> > 
> > Why would it fail?  If governor->max_transition_latency is non-zero, but less
> > than UNIT_MAX, the condition checked will be true to my eyes.
> 
> Bad wording. Sorry.
> 
> I meant, this 'if' check will always succeed (as you also noted), and
> so we will always get the error message reported in this patch.

Not always, but for drivers setting cpuinfo.transition_latency to CPUFREQ_ETERNAL.

Thanks,
Rafael