Re: [PATCH v2 4/7] cpufreq: report whether cpufreq supports Frequency Invariance (FI)

Viresh Kumar
2020-08-04T06:48:16Z

On 03-08-20, 16:24, Ionela Voinescu wrote:
> Right, cpufreq_register_driver() should check that at least one of them
> is present

> (although currently cpufreq_register_driver() will return
> -EINVAL if .fast_switch() alone is present - something to be fixed).

I think it is fine as there is no guarantee from cpufreq core if
.fast_switch() will get called and so target/target_index must be
present. We can't do fast-switch today without schedutil (as only that
enables it) and if a notifier gets registered before the driver, then
we are gone again.

> Will do, on both accounts.
>
>
> > > + static_branch_enable_cpuslocked(&cpufreq_set_freq_scale);
> > > + pr_debug("%s: Driver %s can provide frequency invariance.",
> > > + __func__, driver->name);
> >
> > I think a simpler print will work well too.
> >
> > pr_debug("Freq invariance enabled");
> >
>
> I think the right way of reporting this support is important here.

Yeah, we can't say it is enabled as you explained, though I meant
something else here then, i.e. getting rid of driver name and
unimportant stuff. What about this now:

pr_debug("supports frequency invariance");

This shall get printed as this finally:

cpufreq: supports frequency invariance

--
viresh