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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Tue, 27 Feb 2024 04:26:06 +0200
Message-ID: <CAA8EJprvk-MMrYhG0baT0OyOAGwOTVeHQvKmrvJPrc+KdbJaDw@mail.gmail.com>
Subject: Re: [PATCH 0/2] Match panel hash for overridden mode
To: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>, Neil Armstrong <neil.armstrong@linaro.org>, 
	Jessica Zhang <quic_jesszhan@quicinc.com>, Sam Ravnborg <sam@ravnborg.org>, 
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
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On Tue, 27 Feb 2024 at 03:10, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
>
> On Mon, Feb 26, 2024 at 4:37=E2=80=AFPM Dmitry Baryshkov
> <dmitry.baryshkov@linaro.org> wrote:
> >
> > On Sat, 24 Feb 2024 at 00:40, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
> > >
> > > This series is a follow up for 1a5e81de180e ("Revert "drm/panel-edp: =
Add
> > > auo_b116xa3_mode""). It's found that 2 different AUO panels use the s=
ame
> > > product id. One of them requires an overridden mode, while the other =
should
> > > use the mode directly from edid.
> > >
> > > Since product id match is no longer sufficient, EDP_PANEL_ENTRY2 is e=
xtended
> > > to check the crc hash of the entire edid base block.
> >
> > Do you have these EDIDs posted somewhere? Can we use something less
> > cryptic than hash for matching the panel, e.g. strings from Monitor
> > Descriptors?
> >
>
> Panel 1:
>
> 00 ff ff ff ff ff ff 00 06 af 5c 40 00 00 00 00
> 00 1a 01 04 95 1a 0e 78 02 99 85 95 55 56 92 28
> 22 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
> 01 01 01 01 01 01 12 1b 56 5a 50 00 19 30 30 20
> 46 00 00 90 10 00 00 18 00 00 00 0f 00 00 00 00
> 00 00 00 00 00 00 00 00 00 20 00 00 00 fe 00 41
> 55 4f 0a 20 20 20 20 20 20 20 20 20 00 00 00 fe
> 00 42 31 31 36 58 41 4b 30 31 2e 30 20 0a 00 cc
>
> ----------------
>
> Block 0, Base EDID:
>   EDID Structure Version & Revision: 1.4
>   Vendor & Product Identification:
>     Manufacturer: AUO
>     Model: 16476
>     Made in: 2016
>   Basic Display Parameters & Features:
>     Digital display
>     Bits per primary color channel: 6
>     DisplayPort interface
>     Maximum image size: 26 cm x 14 cm
>     Gamma: 2.20
>     Supported color formats: RGB 4:4:4
>     First detailed timing includes the native pixel format and
> preferred refresh rate
>   Color Characteristics:
>     Red  : 0.5839, 0.3330
>     Green: 0.3378, 0.5712
>     Blue : 0.1582, 0.1328
>     White: 0.3134, 0.3291
>   Established Timings I & II: none
>   Standard Timings: none
>   Detailed Timing Descriptors:
>     DTD 1:  1366x768    60.020 Hz 683:384  47.596 kHz   69.300 MHz
> (256 mm x 144 mm)
>                  Hfront   48 Hsync  32 Hback  10 Hpol N
>                  Vfront    4 Vsync   6 Vback  15 Vpol N
>     Manufacturer-Specified Display Descriptor (0x0f): 00 0f 00 00 00
> 00 00 00 00 00 00 00 00 00 00 20 '............... '
>     Alphanumeric Data String: 'AUO'
>     Alphanumeric Data String: 'B116XAK01.0 '
> Checksum: 0xcc
>
>
> Panel 2:
>
> 00 ff ff ff ff ff ff 00 06 af 5c 40 00 00 00 00
> 00 19 01 04 95 1a 0e 78 02 99 85 95 55 56 92 28
> 22 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
> 01 01 01 01 01 01 ce 1d 56 ea 50 00 1a 30 30 20
> 46 00 00 90 10 00 00 18 d4 17 56 ea 50 00 1a 30
> 30 20 46 00 00 90 10 00 00 18 00 00 00 fe 00 41
> 55 4f 0a 20 20 20 20 20 20 20 20 20 00 00 00 fe
> 00 42 31 31 36 58 41 4e 30 34 2e 30 20 0a 00 94
>
> ----------------
>
> Block 0, Base EDID:
>   EDID Structure Version & Revision: 1.4
>   Vendor & Product Identification:
>     Manufacturer: AUO
>     Model: 16476
>     Made in: 2015
>   Basic Display Parameters & Features:
>     Digital display
>     Bits per primary color channel: 6
>     DisplayPort interface
>     Maximum image size: 26 cm x 14 cm
>     Gamma: 2.20
>     Supported color formats: RGB 4:4:4
>     First detailed timing includes the native pixel format and
> preferred refresh rate
>   Color Characteristics:
>     Red  : 0.5839, 0.3330
>     Green: 0.3378, 0.5712
>     Blue : 0.1582, 0.1328
>     White: 0.3134, 0.3291
>   Established Timings I & II: none
>   Standard Timings: none
>   Detailed Timing Descriptors:
>     DTD 1:  1366x768    60.059824 Hz 683:384   47.688 kHz
> 76.300000 MHz (256 mm x 144 mm)
>                  Hfront   48 Hsync  32 Hback  154 Hpol N
>                  Vfront    4 Vsync   6 Vback   16 Vpol N
>     DTD 2:  1366x768    48.016373 Hz 683:384   38.125 kHz
> 61.000000 MHz (256 mm x 144 mm)
>                  Hfront   48 Hsync  32 Hback  154 Hpol N
>                  Vfront    4 Vsync   6 Vback   16 Vpol N
>     Alphanumeric Data String: 'AUO'
>     Alphanumeric Data String: 'B116XAN04.0 '
> Checksum: 0x94
>
> In this example, Descriptors can also be used to distinguish. But it's
> possible that the name field is also reused by mistake, for the same
> reason as model id is reused.

Thank you! Let's settle the discussion at the cover letter.

>
>
> > >
> > > Hsin-Yi Wang (2):
> > >   drm_edid: Add a function to get EDID base block
> > >   drm/panel: panel-edp: Match with panel hash for overridden modes
> > >
> > >  drivers/gpu/drm/drm_edid.c        | 55 +++++++++++++++-------------
> > >  drivers/gpu/drm/panel/panel-edp.c | 60 ++++++++++++++++++++++++++---=
--
> > >  include/drm/drm_edid.h            |  3 +-
> > >  3 files changed, 84 insertions(+), 34 deletions(-)
> > >
> > > --
> > > 2.44.0.rc0.258.g7320e95886-goog
> > >
> >
> >
> > --
> > With best wishes
> > Dmitry


--=20
With best wishes
Dmitry