Re: [PATCH 2/7] cpufreq: dt: Register an Energy Model

From: Quentin Perret <quentin.perret@arm.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: mark.rutland@arm.com, nm@ti.com, lorenzo.pieralisi@arm.com,
	devicetree@vger.kernel.org, sboyd@kernel.org, rjw@rjwysocki.net,
	mka@chromium.org, linux-pm@vger.kernel.org, liviu.dudau@arm.com,
	linux-kernel@vger.kernel.org, robh+dt@kernel.org,
	sudeep.holla@arm.com, dietmar.eggemann@arm.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/7] cpufreq: dt: Register an Energy Model
Date: Tue, 29 Jan 2019 09:10:43 +0000	[thread overview]
Message-ID: <20190129091041.et46clxo3lci34xf@queper01-lin> (raw)
In-Reply-To: <20190129053041.ymyhfusj6eimpxfu@vireshk-i7>

On Tuesday 29 Jan 2019 at 11:00:41 (+0530), Viresh Kumar wrote:
> On 28-01-19, 16:55, Quentin Perret wrote:
> > Now that PM_OPP provides a helper function to estimate the power
> > consumed by CPUs, make sure to try and register an Energy Model (EM)
> > from cpufreq-dt, hence ensuring interested subsystems (the task
> > scheduler, for example) can make use of that information when available.
> > 
> > Signed-off-by: Quentin Perret <quentin.perret@arm.com>
> > ---
> >  drivers/cpufreq/cpufreq-dt.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> > index e58bfcb1169e..7556e07e7a9f 100644
> > --- a/drivers/cpufreq/cpufreq-dt.c
> > +++ b/drivers/cpufreq/cpufreq-dt.c
> > @@ -16,6 +16,7 @@
> >  #include <linux/cpu_cooling.h>
> >  #include <linux/cpufreq.h>
> >  #include <linux/cpumask.h>
> > +#include <linux/energy_model.h>
> >  #include <linux/err.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > @@ -152,6 +153,7 @@ static int resources_available(void)
> >  
> >  static int cpufreq_init(struct cpufreq_policy *policy)
> >  {
> > +	struct em_data_callback em_cb = EM_DATA_CB(of_dev_pm_opp_get_cpu_power);
> 
> Hmm, so all the earlier comments regarding prototype of this routine are invalid
> because of this.

Right.

> 
> >  	struct cpufreq_frequency_table *freq_table;
> >  	struct opp_table *opp_table = NULL;
> >  	struct private_data *priv;
> > @@ -160,7 +162,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
> >  	unsigned int transition_latency;
> >  	bool fallback = false;
> >  	const char *name;
> > -	int ret;
> > +	int ret, nr_opp;
> >  
> >  	cpu_dev = get_cpu_device(policy->cpu);
> >  	if (!cpu_dev) {
> > @@ -237,6 +239,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
> >  		ret = -EPROBE_DEFER;
> >  		goto out_free_opp;
> >  	}
> > +	nr_opp = ret;
> 
> Instead use nr_opp instead of ret while calling dev_pm_opp_get_opp_count().

Will do.

> 
> >  
> >  	if (fallback) {
> >  		cpumask_setall(policy->cpus);
> > @@ -280,6 +283,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
> >  	policy->cpuinfo.transition_latency = transition_latency;
> >  	policy->dvfs_possible_from_any_cpu = true;
> >  
> > +	em_register_perf_domain(policy->cpus, nr_opp, &em_cb);
> > +
> >  	return 0;
> >  
> >  out_free_cpufreq_table:
> > -- 
> > 2.20.1
> 
> -- 
> viresh

Thanks,
Quentin

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