AMD HDMI HPD hardware bypass

    Hi LE community,

    As I spent some time on this issue I though doing a post for the record could be a good idea, here it is.

    My setup is a SFF Dell OptiPlex 3020 with a dual boot Debian / LibreELEC to have a gaming station / media center. I upgraded CPU to an Intel i5-4690 and I lastly went from an Nvidia GT710 to an AMD WX4100 LowProfile.

    With the GT710 I was able to just start the computer and play music or send a YouTube link and listen to my music. With the WX4100 I had to turn on my VP before starting the computer which is annoying because it takes a time I don't want to spend on this, and power cycling on and off the lamp on my VP is probably not a good idea.

    I read this page of the documentation : https://wiki.libreelec.tv/configuration/edid which states : "AMD/ATI GPU's are not supported" uh :(.

    I read that EDID could be injected in the kernel : https://wiki.archlinux.org/title/Kernel_m…_modes_and_EDID but LibreELEC may a custom boot procedure right ? Plus EDID.bin had to be at the right place, I expected too much learning to succeed this way.

    I read this thread that gave me the solution : https://hardforum.com/threads/trick-…ays-on.1888194/

    I had in my stuffs a cheap HDMI A M/F breakout board so I lifted the 19th pin on the VP side and soldered a 10kΩ resistor between pin 18 and 19. Et voilà. I can listen to music/play videos without the need to turn on/off my VP.

    A picture of the board will follow.

    The "getedid create" process should work the same on all hardware we support these days; perhaps with a few niche exceptions among ARM SoC boards, but AMD cards should be fine. There's no harm in experimenting anyway and "getedid delete" will always clear-up the applied config if it didn't work.