linux-kernel - Re: [PATCH 8/8] cpufreq: vexpress: Use auto-registration for energy model

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Date:   Tue, 10 Aug 2021 15:42:25 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Lukasz Luba <lukasz.luba@....com>
Cc:     Rafael Wysocki <rjw@...ysocki.net>,
        Vincent Donnefort <vincent.donnefort@....com>,
        Sudeep Holla <sudeep.holla@....com>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 8/8] cpufreq: vexpress: Use auto-registration for energy
 model

On 10-08-21, 11:11, Lukasz Luba wrote:
> 
> 
> On 8/10/21 11:06 AM, Viresh Kumar wrote:
> > On 10-08-21, 11:05, Lukasz Luba wrote:
> > > I can see that this driver calls explicitly the
> > > of_cpufreq_cooling_register()
> > > It does this in the cpufreq_driver->ready() callback
> > > implementation: ve_spc_cpufreq_ready()
> > > 
> > > With that in mind, the new code in the patch 1/8, which
> > > registers the EM, should be called even earlier, above:
> > > ---------------------8<---------------------------------
> > > /* Callback for handling stuff after policy is ready */
> > > 	if (cpufreq_driver->ready)
> > > 		cpufreq_driver->ready(policy);
> > > ------------------->8----------------------------------
> > 
> > Thanks. I will look at this sequencing issue again.
> > 
> > > This also triggered a question:
> > > If this new flag can be set in the cpufreq driver which hasn't set
> > > CPUFREQ_IS_COOLING_DEV
> > > ?
> > 
> > Why not ?
> 
> I thought someone could try to call cpufreq_cooling_register()
> from the cpufreq driver init function, but it's not possible. I have
> just checked that, so should be good with these two flags being
> independent and working fine.

Ahh, I see. Great.

-- 
viresh