linux-kernel - Re: [PATCH v1] drm/panel-edp: Add panels with conservative timings

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Message-ID: <CA+hhT3-77s+jjoBGw_fWWjsvO1kDu_JTDHgj=q-pEXcrkzPkLQ@mail.gmail.com>
Date: Sun, 21 Jul 2024 18:59:50 +0800
From: Terry Hsiao <terry_hsiao@...pal.corp-partner.google.com>
To: Doug Anderson <dianders@...omium.org>
Cc: linux-kernel@...r.kernel.org, Neil Armstrong <neil.armstrong@...aro.org>, 
	Jessica Zhang <quic_jesszhan@...cinc.com>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>, 
	dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH v1] drm/panel-edp: Add panels with conservative timings

Hi Doug,

Thank you for your reply.
The patch has been modified and will be sent to you shortly.

The timings are set based on the panel datasheets in IssueTracker
(https://partnerissuetracker.corp.google.com/issues/348109270)
B116XTN02.3: B116XTN02.3(HW 9A)_HP_ Functional Spec_0617Y24.pdf
B116XAN06.1: B116XAN06.1_7A_HP_ Final Functional Spec 0617Y24.pdf
B116XAT04.1: B116XAT04.1 HW 0 A(HH)_ Pre Functional Spec_HP_ 0425Y24.pdf
NV116WHM-A4D: NV116WHM-A4D V8.0 Teacake  Product Specification-20240416.pdf
N116BCA-EA2: Approval Specification N116BCA-EA2_C3_20231212.pdf
N116BCP-EA2: TFT-LCD Tentative N116BCP-EA2 C2 for HP Ver 0.2-240502.pdf

On page 24 of the N116BCP-EA2
datasheet(https://partnerissuetracker.corp.google.com/action/issues/348109270/attachments/57530666?download=false),
the value for t9 as disable is "null".

If I have misunderstood what you mean, please correct me.

Thank you,

On Wed, Jul 17, 2024 at 10:58 PM Doug Anderson <dianders@...omium.org> wrote:
>
> Hi,
>
> On Wed, Jul 17, 2024 at 2:39 AM Terry Hsiao
> <terry_hsiao@...pal.corp-partner.google.com> wrote:
> >
> > The 6 panels are used on Mediatek MT8186 Chromebooks
> > - B116XAT04.1  (06AF/B4C4)
> > - NV116WHM-A4D (09E5/FA0C)
> > - N116BCP-EA2  (0DAE/6111)
> > - B116XTN02.3  (06AF/AA73)
> > - B116XAN06.1  (06AF/99A1)
> > - N116BCA-EA2  (0DAE/5D11)
> >
> > Signed-off-by: Terry Hsiao <terry_hsiao@...pal.corp-partner.google.com>
> > ---
> >  drivers/gpu/drm/panel/panel-edp.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
>
> Please resend with a better patch subject, like "drm/panel-edp: Add 6
> panels used by MT8186 Chromebooks".
>
> Also: are you adding timings based on the datasheets, or are you just
> guessing here? The previous patches that added "conservative" timings
> were because the Chromebooks involved were really old and couldn't be
> tracked down and folks couldn't find the relevant datasheets. In the
> case of MT8188 I'd expect you to be adding timings based on the
> datasheets. Please confirm that you are.
>
> If possible, it's really nice to have the raw EDIDs for the panels in
> the commit message in case someone needs it later.
>
>
> > diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
> > index f85a6404ba58..ac280607998f 100644
> > --- a/drivers/gpu/drm/panel/panel-edp.c
> > +++ b/drivers/gpu/drm/panel/panel-edp.c
> > @@ -1845,8 +1845,11 @@ static const struct edp_panel_entry edp_panels[] = {
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0x635c, &delay_200_500_e50, "B116XAN06.3"),
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0x639c, &delay_200_500_e50, "B140HAK02.7"),
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0x723c, &delay_200_500_e50, "B140XTN07.2"),
> > +       EDP_PANEL_ENTRY('A', 'U', 'O', 0x73aa, &delay_200_500_e50, "B116XTN02.3"),
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0x8594, &delay_200_500_e50, "B133UAN01.0"),
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0xd497, &delay_200_500_e50, "B120XAN01.0"),
> > +       EDP_PANEL_ENTRY('A', 'U', 'O', 0xa199, &delay_200_500_e50, "B116XAN06.1"),
>
> Please keep this sorted. For instance, 0xa199 should come _before_
> 0xd497, right?
>
>
> > +       EDP_PANEL_ENTRY('A', 'U', 'O', 0xc4b4, &delay_200_500_e50, "B116XAT04.1"),
> >         EDP_PANEL_ENTRY('A', 'U', 'O', 0xf390, &delay_200_500_e50, "B140XTN07.7"),
> >
> >         EDP_PANEL_ENTRY('B', 'O', 'E', 0x0607, &delay_200_500_e200, "Unknown"),
> > @@ -1901,6 +1904,7 @@ static const struct edp_panel_entry edp_panels[] = {
> >         EDP_PANEL_ENTRY('B', 'O', 'E', 0x0b56, &delay_200_500_e80, "NT140FHM-N47"),
> >         EDP_PANEL_ENTRY('B', 'O', 'E', 0x0c20, &delay_200_500_e80, "NT140FHM-N47"),
> >         EDP_PANEL_ENTRY('B', 'O', 'E', 0x0cb6, &delay_200_500_e200, "NT116WHM-N44"),
> > +       EDP_PANEL_ENTRY('B', 'O', 'E', 0x0cfa, &delay_200_500_e50, "NV116WHM-A4D"),
> >
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x1130, &delay_200_500_e50, "N116BGE-EB2"),
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x1132, &delay_200_500_e80_d50, "N116BGE-EA2"),
> > @@ -1916,8 +1920,10 @@ static const struct edp_panel_entry edp_panels[] = {
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x1156, &delay_200_500_e80_d50, "Unknown"),
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x1157, &delay_200_500_e80_d50, "N116BGE-EA2"),
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x115b, &delay_200_500_e80_d50, "N116BCN-EB1"),
> > +       EDP_PANEL_ENTRY('C', 'M', 'N', 0x115d, &delay_200_500_e80_d50, "N116BCA-EA2"),
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x115e, &delay_200_500_e80_d50, "N116BCA-EA1"),
> >         EDP_PANEL_ENTRY('C', 'M', 'N', 0x1160, &delay_200_500_e80_d50, "N116BCJ-EAK"),
> > +       EDP_PANEL_ENTRY('C', 'M', 'N', 0x1161, &delay_200_500_e80, "N116BCP-EA2"),
>
> It looks suspicious that all the panels around this one need 50 ms for
> disable but yours doesn't. While it's certainly possible that things
> changed for this panel, it's worth double-checking.
>
> -Doug