Re: [PATCH 2/5] arm64: dts: qcom: sa8540p: use sa8540p gpucc compatible

[Johan Hovold <johan@kernel.org>]

On Tue, Mar 26, 2024 at 05:02:43PM +0100, Krzysztof Kozlowski wrote:
> On 26/03/2024 15:01, Johan Hovold wrote:
> > The SA8540P platform is closely related to SC8280XP but differs in that
> > it uses an external supply for the GX power domain.
> > 
> > Use the new SA8540P compatible string for the GPU clock controller so
> > that the OS can determine which resources to look for.
> > 
> > Note that a fallback SC8280XP compatible is added temporarily to avoid
> > any temporary regressions for sa8295p-adp.
> > 
> > Fixes: fd5821a1a83c ("arm64: dts: qcom: sa8540p: Drop gfx.lvl as power-domain for gpucc")
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> >  arch/arm64/boot/dts/qcom/sa8540p.dtsi | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/sa8540p.dtsi b/arch/arm64/boot/dts/qcom/sa8540p.dtsi
> > index 23888029cc11..3b31a9ea3492 100644
> > --- a/arch/arm64/boot/dts/qcom/sa8540p.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sa8540p.dtsi
> > @@ -168,6 +168,8 @@ opp-2592000000 {
> >  };
> >  
> >  &gpucc {
> > +	compatible = "qcom,sa8540p-gpucc", "qcom,sc8280xp-gpucc";
> 
> This introduces new dtbs_check failures. Please fix the binding and drop
> the last patch in the series.

I know, and this is done on purpose.

I doubt anyone cares if the sa8295p GPU breaks for one commit in case
this series goes in through the same tree or even for a couple of RCs in
case they go in through separate trees.

But we recently had a similar discussion about a bluetooth fix and
whatever course of action I would have chosen here, someone is bound to
whine.

In this case I figured it was worth doing the extra work. But this is
just a temporary workaround as "qcom,sa8540p-gpucc" is not truly
compatible with "qcom,sc8280xp-gpucc" as only the former depends on the
external supply.

Heck, I even spelled it out in the commit message...

Johan