Re: [PATCH v2 0/2] Introduce 'advanced' Energy Model in DT

From: Viresh Kumar
Date: Wed Feb 23 2022 - 06:27:38 EST


On 23-02-22, 11:22, Lukasz Luba wrote:
> On 2/23/22 10:43, Viresh Kumar wrote:
> > On 23-02-22, 10:52, Daniel Lezcano wrote:
> > > why not extend the energy model to any kind of devices?
> >
> > FWIW, the OPP core supports a wide range of devices now, not just CPUs.

There are many other devices which still use Freq.

> Is that the "opp-level" thing which would allow that?

For power supplies/regulators, we don't have freq and they use level, right.

Also for interconnect we use bandwidth, in a similar way.

> I can see some DT files with regulators(?) using it e.g. [1].
> It looks flexible, the opp-hz is not hard requirement,
> the opp-level can be used instead IIUC.

Right.

> It might be a next step which might meet Daniel's needs.
> If that 'level' can be any number and frequency is not available
> then EM must have 'level' filed in the struct em_perf_state
> for this kind of new devices. I'm open for such change.
> We can discuss this as a next step. We would need to find some examples
> how this new thing would be used.
>
> [1] https://elixir.bootlin.com/linux/v5.17-rc5/source/arch/arm/boot/dts/tegra20-peripherals-opp.dtsi#L4

--
viresh