Raspberry Pi 4 Motorola Awtrix Lapdock Resolution fix

The Raspberry PI 4 with Raspberry OS (Bookworm) provides the wrong resolution in combination with the Lapdock from Motorola, resulting in an incorrect display.

To fix this under Wayland (Raspberry Pi OS Bookworm) you must force the drm kms system to use a resolution of 1368x768@60 Hz. On the Raspberry Pi4 execute

$ sudo mkdir /usr/lib/firmware/edid
$ wget https://github.com/bjoernh/Rpi4-motorola-Awtrix-lapdock/raw/refs/heads/main/1368x768_60.bin
$ sudo mv 1368x768_60.bin /usr/lib/firmware/edid/

Edit /boot/firmware/cmdline.txt and append this string to the end of the line

 video=HDMI-A-1:1368x768M@60D drm_kms_helper.edid_firmware=edid/1368x768_60.bin

Reboot the Pi and the Lapdock should now works with the Rapberry Pi 4 and Wayland :)

Tested with Rasberry OS 64bit Bookworm (build date November 19th 2024)

Create EDID Date file by your own

If you don't trust the binary, you can create it by your own.

$ sudo apt install zsh edid-decode automake dos2unix
$ wget https://github.com/akatrevorjay/edid-generator/archive/master.zip
$ unzip master.zip 
$ cd edid-generator-master
$ ./modeline2edid - <<< 'Modeline "1368x768_60"  85.86  1368 1440 1584 1800  768 769 772 795  -HSync +Vsync'
$ make

This gives you an EDID binary file 1368x768_60.bin.