Re: [PATCH 2/3] arm64: dts: qcom: eliza: Add CX power domain to GCC

[Abel Vesa]

On 26-03-23 21:15:12, Bjorn Andersson wrote:
> On Sun, Mar 22, 2026 at 06:08:20PM +0200, Abel Vesa wrote:
> > Recent discussions off-list highlighted that the GCC should vote for the
> > RPMh CX power domain on Qualcomm platforms.
> 
> Your commit message should describe the problem that the patch is trying
> to solve, not the story about how the patch came to be.

Sure. Will fix.

> 
> > Without this, RPMh may not aggregate the correct load for the CX rail,
> 
> "may not"?
> 
> In what case will it aggregate the client votes cast on the GDSCs
> aggregate to anything without the power-domains property?

So my understanding was that RPMh firmware aggregates votes
internally as it knows the actual parent-child relationship and we were
supposed to replicate that exactly in kernel for reliability purposes.

Meaning, in theory it should know to aggregate proper load for the CX
based on GDSCs voting, it's just that it isn't always a sure thing.

Maybe I missunderstood it though.

> 
> > potentially leading to voltage
> > drops and system instability.
> > 
> > Add the missing power-domains property to associate GCC with RPMHPD_CX.
> > 
> 
> I think the commit message should be something like:
> 
> """
> Unless CX is declared the power-domain of GCC votes (power and
> performance) on the GDSCs provided by GCC will not propagate to the CX,
> which might result in under-voltage conditions.
> 
> Add the missing power-domains property to associate GCC with RPMHPD_CX.
> """

Sure, will respin with this commit message.

Thanks for reviewing.