How to check EDID with DRM interface. Wrong/bad output resolution

Hi @f.mazur,
It seems that you can read the detected EDID of a connected HDMI monitor on apalis IMX8QM with:

root@apalis-imx8:/# hexdump -C /sys/class/drm/card1-HDMI-A-1/edid
00000000  00 ff ff ff ff ff ff 00  41 0c cd c0 8a d5 00 00  |........A.......|
00000010  18 1f 01 03 80 29 17 78  2a 0c c5 a4 57 50 a1 28  |.....).x*...WP.(|
00000020  0d 50 54 bd 4a 00 81 80  81 c0 81 40 01 01 01 01  |.PT.J......@....|
00000030  01 01 01 01 01 01 66 21  56 aa 51 00 1e 30 46 8f  |......f!V.Q..0F.|
00000040  33 00 9a e6 10 00 00 1e  00 00 00 ff 00 41 46 43  |3............AFC|
00000050  32 31 32 34 30 35 34 36  36 36 00 00 00 fc 00 50  |2124054666.....P|
00000060  48 4c 20 31 39 33 56 35  0a 20 20 20 00 00 00 fd  |HL 193V5.   ....|
00000070  00 38 4c 1e 53 11 00 0a  20 20 20 20 20 20 01 7d  |.8L.S...      .}|
00000080  02 03 16 b1 4b 01 02 03  06 07 11 12 13 15 16 04  |....K...........|
00000090  65 03 0c 00 10 00 01 1d  00 72 51 d0 1e 20 6e 28  |e........rQ.. n(|
000000a0  55 00 9a e6 10 00 00 1e  8c 0a d0 8a 20 e0 2d 10  |U........... .-.|
000000b0  10 3e 96 00 9a e6 10 00  00 18 8c 0a d0 90 20 40  |.>............ @|
000000c0  31 20 0c 40 55 00 9a e6  10 00 00 18 00 00 00 00  |1 .@U...........|
000000d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
000000f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 bc  |................|
00000100

In order to force specific modes you could have a look at this:

And in this document you’ll find information about how to build the custom EDID binary.
Please let me know if this helps you,
Rafael Beims

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