Re: [PATCH v2 4/7] cpufreq: report whether cpufreq supports Frequency Invariance (FI)
From: Ionela Voinescu
Date: Wed Aug 05 2020 - 07:09:34 EST
On Tuesday 04 Aug 2020 at 12:16:56 (+0530), Viresh Kumar wrote:
> 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