Re: [PATCH v1 00/30] Introduce core voltage scaling for NVIDIA Tegra20/30 SoCs

Dmitry Osipenko
2020-11-05T15:22:22Z

05.11.2020 12:45, Ulf Hansson пишет:
...
> I need some more time to review this, but just a quick check found a
> few potential issues...

Thank you for starting the review! I'm pretty sure it will take a couple
revisions until all the questions will be resolved :)

> The "core-supply", that you specify as a regulator for each
> controller's device node, is not the way we describe power domains.
> Instead, it seems like you should register a power-domain provider
> (with the help of genpd) and implement the ->set_performance_state()
> callback for it. Each device node should then be hooked up to this
> power-domain, rather than to a "core-supply". For DT bindings, please
> have a look at Documentation/devicetree/bindings/power/power-domain.yaml
> and Documentation/devicetree/bindings/power/power_domain.txt.
>
> In regards to the "sync state" problem (preventing to change
> performance states until all consumers have been attached), this can
> then be managed by the genpd provider driver instead.

I'll need to take a closer look at GENPD, thank you for the suggestion.

Sounds like a software GENPD driver which manages clocks and voltages
could be a good idea, but it also could be an unnecessary
over-engineering. Let's see..