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

[Quentin Perret]

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

Would that work ?

Thanks,
Quentin