Re: [PATCH 0/2] Match panel hash for overridden mode

Hsin-Yi Wang
2024-02-27T01:10:22Z

On Mon, Feb 26, 2024 at 4:37 PM 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 same
> > 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 extended
> > 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.

> >
> > 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