On 01-06-21, 13:12, Stephan Gerhold wrote:
> > + child4: consumer@12341000 {
> > + compatible = "foo,consumer";
> > + reg = <0x12341000 0x1000>;
> > + power-domains = <&parent4>, <&parent5>;
> > + assigned-performance-states = <0>, <256>;
> > + };
>
> Bjorn already asked this in v1 [1]:
>
> > May I ask how this is different from saying something like:
> >
> > required-opps = <&??>, <&rpmpd_opp_svs>;
>
> and maybe this was already discussed further elsewhere. But I think at
> the very least we need some clarification in the commit message + the
> binding documentation how your new property relates to the existing
> "required-opps" binding.
>
> Because even if it might not be implemented at the moment,
> Documentation/devicetree/bindings/power/power_domain.txt actually also
> specifies "required-opps" for device nodes e.g. with the following example:
>
> leaky-device0@12350000 {
> compatible = "foo,i-leak-current";
> reg = <0x12350000 0x1000>;
> power-domains = <&power 0>;
> required-opps = <&domain0_opp_0>;
> };
>
> It looks like Viresh added that in commit e856f078bcf1
> ("OPP: Introduce "required-opp" property").
>
> And in general I think it's a bit inconsistent that we usually refer to
> performance states with phandles into the OPP table, but the
> assigned-performance-states suddenly use "raw numbers".
I must have missed that discussion, sorry about that.
The required-opps property, when present in device's node directly, is about the
(default) OPPs to choose for that device's normal functioning as they may not do
DVFS.
Good point Stephan.
--
viresh
