Re: [PATCH 1/3] arm64: defconfig: Enable CONFIG_ENERGY_MODEL

[Quentin Perret]

Hi Daniel,

On Thursday 28 Mar 2019 at 18:27:49 (+0100), Daniel Lezcano wrote:
> On 28/03/2019 11:22, Quentin Perret wrote:
> >> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> >> index 2d9c39033c1a..3c09bdaaefd3 100644
> >> --- a/arch/arm64/configs/defconfig
> >> +++ b/arch/arm64/configs/defconfig
> >> @@ -97,6 +97,7 @@ CONFIG_XEN=y
> >>  CONFIG_COMPAT=y
> >>  CONFIG_HIBERNATION=y
> >>  CONFIG_WQ_POWER_EFFICIENT_DEFAULT=y
> >> +CONFIG_ENERGY_MODEL=n
> > 
> > Hmm, sorry I turned this to '=n' for testing and forgot to update the
> > patch. This obviously should be '=y' ...
> 
> I did a test without the ENERGY_MODEL config option set, dhrystone and
> the power_allocator policy on the hikey. The board did not mitigate well
> and ended up rebooting.

OK ... And is the same thing happening if you just run mainline w/o the
dynamic-power-coefficient binding set for example ? The result _should_
be the same. If not, then perhaps I missed something. I'll try to
reproduce on my end. Just to be sure, when you say hikey, you mean
hikey960 ? Or 620 ? In any case, thanks for testing :-)

> May be the cpu cooling Kconfig option should add
> a SELECT or a DEPENDS on ENERGY_MODEL ?

Right, I've been wondering the same thing. I'm not a big fan of 'select'
because enabling ENERGY_MODEL automatically for the thermal stuff will
also happen to enable other things (EAS) without the user knowing. So
I'd rather keep the ENERGY_MODEL option explicit.

But perhaps having THERMAL_GOV_POWER_ALLOCATOR 'depend on ENERGY_MODEL'
could work. It's just that there is no _strong_ dependency, the IPA code
isn't supposed to crash even if there is no EM ...

Thanks,
Quentin