Re: [PATCH 3/4] arm64: dts: qcom: sc8280xp: Add initial support for Ntmer TW220

[Pengyu Luo <mitltlatltl@gmail.com>]

On Sat, Aug 2, 2025 at 1:27 AM Dmitry Baryshkov
<dmitry.baryshkov@oss.qualcomm.com> wrote:
>
> On Fri, Aug 01, 2025 at 10:27:33PM +0800, Pengyu Luo wrote:
> > On Fri, Aug 1, 2025 at 8:29 PM Konrad Dybcio
> > <konrad.dybcio@oss.qualcomm.com> wrote:
> > >
> > > On 7/31/25 5:05 AM, Pengyu Luo wrote:
> > > > Linux:
> > > >> ae94000 20050001 000001f3 0000000b dddd1011
> > > >> ae94010 00009130 31211101 3e2e1e0e 00001900
> > > >> ae94020 00000000 05190019 064c000c 065f0528
> > > >> ae94030 00060000 00000000 00040000 14000000
> > > >> ae94040 06100006 00003c2c 00001000 00000008
> > > > Windows:
> > > >> ae94000 20050001 000001f7 00000008 00001010
> > > >> ae94010 00009130 31211101 3e2e1e0e 00001900
> > > >> ae94020 00000000 05320032 064c000c 065f0551
> > > >> ae94030 000c0000 00000000 00040000 14000000
> > > >> ae94040 00100008 00013c2c 9bb9b000 00000004
> > >
> > > 0xae94008 differs, bits 0 and 1 say that the cmd mode engine
> > > is busy doing something (did you set MIPI_DSI_MODE_VIDEO?)
> > >
> >
> > Yes. I can confirm MIPI_DSI_MODE_VIDEO is set.
> >
> > Speaking of cmd mode, I still have no idea why DSI_CTRL_CMD_MODE_EN
> > (BIT(2) of 0xae94004) is enabled on Windows.
> >
> > > 0xae94024 says:
> > > Linux:
> > > ACTIVE_H_END=1305
> > > ACTIVE_H_START=25
> > > Windows:
> > > ACTIVE_H_END=1330
> > > ACTIVE_H_START=50
> > >
> > > 0xae9402c:
> > > Linux:
> > > VTOTAL=1631
> > > HTOTAL=1320
> > > Windows:
> > > VTOTAL=1631
> > > HTOTAL=1361
> > >
> > > 0xae94030:
> > > Linux:
> > > HS_END=6
> > > Windows:
> > > HS_END=12
> > >
> >
> > I believe we can ignore them now, I found the final dump and verified
> > it’s correct. Previously, I mistakenly halved the porch timings:
> >
> > Incorrect:
> > .hsync_total = (1280 + (32 + 12 + 38) / 2) * 2.
>
> If you halved the porches... Is this panel using a single DSI host or
> two DSI hosts? In the latter case you need to assign parents for DSI
> clocks (see how it's done on the sdm845-db845c)
>

Two dsi hosts. I was using your OOT patches for dual dsi cases until
you upstreamed them. So I have set

assigned-clock-parents = <&mdss_dsi0_phy DSI_BYTE_PLL_CLK>,
                         <&mdss_dsi0_phy DSI_PIXEL_PLL_CLK>;

as you did in your msm-next repo.

Best wishes,
Pengyu