Re: [PATCH] arm64: dts: qcom: sc8280xp-huawei-gaokun3: Add dsi panel DT node

[Pengyu Luo]

On Tue, Jun 30, 2026 at 6:34 PM Konrad Dybcio
<konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>
> On 6/30/26 12:30 PM, Pengyu Luo wrote:
> > On Tue, Jun 30, 2026 at 6:29 PM Konrad Dybcio
> > <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
> >>
> >> On 6/30/26 11:28 AM, Pengyu Luo wrote:
> >>> On Tue, Jun 30, 2026 at 5:18 PM Konrad Dybcio
> >>> <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
> >>>>
> >>>> On 6/30/26 6:22 AM, Pengyu Luo wrote:
> >>>>> DSI panel driver have been added for a while, so add the DT node to
> >>>>> enable it. vdd{a,s}-supply for dsi, dsi_phy are blank since the DSDT
> >>>>> describes the wrong, no impact after manual disabling these wrong
> >>>>> supplies.
> >>>>>
> >>>>> Signed-off-by: Pengyu Luo <mitltlatltl@xxxxxxxxx>
> >>>>> ---
> >>>>
> >>>> [...]
> >>>>
> >>>>> +&mdss0_dsi0 {
> >>>>> +     /* real vdda is unknown */
> >>>>> +
> >>>>
> >>>> L3B: DSI core 1.2 V (both?)
> >>>> L6B: DSI0/1 PLL and core 0.9 V
> >>>>
> >>>
> >>> Yes, that is what I saw in the DSDT, however, I can disable them
> >>> safely (hack the regulator driver to add a sysfs to handle these
> >>> regulators), the panel works well.
> >>
> >> L3B additionally powers CSIPHY2/3, EDP0/1, REFGEN (probably why it
> >> ends up being on), UFSPHY and USB1_PHY
> >>
> >> L6B additionally powers the same components, minus refgen and USB
> >>
> >
> > No, I confirmed they are totally disabled, since there is a way to check it now.
> > https://lore.kernel.org/linux-arm-msm/20260420-read-rpmh-v3-v4-0-70c152e6c958@xxxxxxxxxxxxxxxx/
>
> This presents you with the status of the votes casted by HLOS, not
> the actual hardware state
>

If so, non-HLOS will vote on some critical regulators to keep them on,
IIRC, once I disabled L9D, system reseted immediately.

> To get the latter, you'd have to dump the SPMI registers
>
I will appreciate it if you provide more information.

Best wishes,
Pengyu

> Konrad