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

From: Viresh Kumar
Date: Wed Jan 30 2019 - 00:18:14 EST


On 29-01-19, 09:15, Quentin Perret wrote:
> On Tuesday 29 Jan 2019 at 10:51:44 (+0530), Viresh Kumar wrote:
> > On 28-01-19, 11:36, Matthias Kaehlcke wrote:
> > > I think this patch will result in error messages at registration on
> > > platforms that use the cpufreq-dt driver and don't specify
> > > 'dynamic-power-coefficient' for the CPUs in the DT. Not sure if that's
> > > a problem as long as the cpufreq initialization succeeds regardless,
> > > it could be seen as a not-so-gentle nudge to add the values.
> >
> > That wouldn't be acceptable.
>
> Fair enough. What I can propose in this case is to have in PM_OPP a
> helper called 'dev_pm_opp_of_register_em()' or something like this. This
> function will check all prerequisites are present (we have the right
> values in DT, and so on) and then call (or not) em_register_perf_domain().
> Then we can make the CPUFreq drivers use that instead of calling
> em_register_perf_domain() directly.

That should be fine.

> That would also make it easy to implement Matthias' suggestion to not
> call em_register_perf_domain() if an EM is already present.

So you will track registration state within the OPP core for that ?
Sorry but that doesn't sound right. What's wrong with having an
unregister helper in energy-model to keep proper code flow everywhere
?

--
viresh