Re: [PATCH 1/3] dt-bindings: display: msm: Allow two MDSS power domains

[Dmitry Baryshkov]

On Thu, Aug 13, 2026 at 03:44:53PM +0800, Yongxing Mou wrote:
> 
> 
> On 7/20/2026 4:49 PM, Konrad Dybcio wrote:
> > On 7/20/26 10:43 AM, Yongxing Mou wrote:
> > > Kaanapali (SM8750) and Glymur use two display power domains.
> > > CORE_GDSC powers the main display hardware while INT2_GDSC
> > > powers a subset of SSPP blocks.
> > 
> > Can they operate independently? Does INT2_GDSC need to be
> > powered on after CORE_GDSC?
> > 
> On Kaanapali, my understanding is that CORE_GDSC and INT2_GDSC should
> generally track the same state, except that INT2_GDSC may be powered down
> when SSPP1 (VIG2/VIG3/DMA5) is unused.
>    - CORE off, INT2 off
>     - CORE on,  INT2 off
>     - CORE on,  INT2 on

What will happen if CORE is off, but INT2 is on?

> > If so, perhaps changing the clock driver to make CORE a parent
> > of INT2 could be the simpler solution
> > 
> > Konrad
> That would still need DT and binding changes -- DPU has to reference
> INT2_GDSC directly to gate it independently, so it can't be hidden in the
> clock driver. The two GDSCs have independent GDSCR registers with no
> HW-enforced sequencing, so they appear to be peers rather than parent/child.

-- 
With best wishes
Dmitry