Re: [PATCH v2 3/3] arm64: dts: qcom: Add INT2 GDSC to Kaanapali DPU

[Dmitry Baryshkov]

On Mon, Oct 12, 2026 at 04:41:21PM +0800, Yongxing Mou wrote:
> 
> 
> On 10/5/2026 9:06 AM, Dmitry Baryshkov wrote:
> > On Tue, Sep 15, 2026 at 05:27:50PM +0800, Yongxing Mou wrote:
> > > The INT2 GDSC on Kaanapali (SM8850) powers a subset of the DPU
> > > source pipes (VIG2/VIG3/DMA5). Add it as a second power domain of
> > > the display-controller (DPU) node, alongside the existing MMCX
> > > performance-state power domain.
> > > 
> > > The MDSS node's CORE_GDSC is unaffected, since it continues to power
> > > the rest of the MDSS hardware on its own.
> > > 
> > > Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
> > > ---
> > >   arch/arm64/boot/dts/qcom/kaanapali.dtsi | 4 +++-
> > >   1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/arch/arm64/boot/dts/qcom/kaanapali.dtsi b/arch/arm64/boot/dts/qcom/kaanapali.dtsi
> > > index ace19b8b12d7..b3e3cd1d311c 100644
> > > --- a/arch/arm64/boot/dts/qcom/kaanapali.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/kaanapali.dtsi
> > > @@ -3619,7 +3619,9 @@ mdss_mdp: display-controller@9801000 {
> > >   				operating-points-v2 = <&mdp_opp_table>;
> > > -				power-domains = <&rpmhpd RPMHPD_MMCX>;
> > > +				power-domains = <&rpmhpd RPMHPD_MMCX>,
> > 
> > Should it continue to be RPMHPD_MMCX or should it become
> > DISP_CC_MDSS_CORE_GDSC?
> > 
> It should remain RPMHPD_MMCX, as this power domain is used by the DPU OPP
> table for performance-state voting.
> 
> DISP_CC_MDSS_CORE_GDSC remains attached to the parent MDSS device because it
> supplies hardware shared across the MDSS subsystem. Since the DPU is a child
> of MDSS, it inherits access to this power domain through the parent-child
> runtime PM hierarchy.
> 
> Only INT2 is attached directly to the DPU, as it exclusively powers a subset
> of the DPU source pipes.

Then should we still attach both CORE and INT2 and ensure that
performance votes on core are translated to the votes on MMCX?

> 
> > > +						<&dispcc DISP_CC_MDSS_CORE_INT2_GDSC>;
> > > +				power-domain-names = "mmcx", "int2";
> > >   				ports {
> > >   					#address-cells = <1>;
> > > 
> > > -- 
> > > 2.43.0
> > > 
> > 
> 

-- 
With best wishes
Dmitry