Re: [PATCH v10 15/15] OPTIONAL: cpufreq: dt: Register an Energy Model

[Quentin Perret]

On Wednesday 09 Jan 2019 at 10:14:51 (-0800), Matthias Kaehlcke wrote:
> I think registering the perf domain only once is fine, since the info
> isn't supposed to change and will likely be used again after
> _exit(). However since we have em_cpu_get() I'd suggest to use it and
> only call em_register_perf_domain() if no perf domain is registered
> yet for the CPU. This makes it more evident that the registration is
> only done once and simplifies error handling (currently not done at
> all), since it's not necessary to check for the special case -EEXIST.

Right, a check on em_cpu_get() on the driver side shouldn't hurt. We
don't actually have upstream drivers using that API yet but I intend to
change that soon. I guess we'll need to have that discussion with each
individual CPUFreq driver maintainer but that hopefully shouldn't be a
problem.

Thanks for the feedback,
Quentin