The latest "bullseye" and "Bookworm" releases use the KMS video driver.
The KMS driver seems less forgiving when the EDID data from the monitor is bad, nonexistant, or malformed.
If you get no display:
probably, your PI OS cannot figure out the EDID data from the monitor, and as such, cannot figure out what resolution to set.
unfortunately, this results in the PI setting none... no display
there have been many reports of "failed video output" which boil down to bad or non-existant EDID data from the monitor. This is an issue more often with the new KMS driver in Bullseye and Bookworm.
note: many HDMI adapters do not pass data in both directions, and can be the cause of no EDID Data. It is recommended to get the proper cable, and not use adapters.
another note: the KMS driver ignores all video settings in config.txt - video mode changes made to this file will have no effect !
however, you can set the resolution manually:
in /boot/cmdline.txt (add to the front/end of the line, NOT a new line)
-- IMPORTANT NOTE: for Bookworm, the file is at /boot/firmware/cmdline.txt !!
video=HDMI-A-1:1024x768@60D
(or whatever resolution you want)
The KMS driver seems less forgiving when the EDID data from the monitor is bad, nonexistant, or malformed.
If you get no display:
probably, your PI OS cannot figure out the EDID data from the monitor, and as such, cannot figure out what resolution to set.
unfortunately, this results in the PI setting none... no display
there have been many reports of "failed video output" which boil down to bad or non-existant EDID data from the monitor. This is an issue more often with the new KMS driver in Bullseye and Bookworm.
note: many HDMI adapters do not pass data in both directions, and can be the cause of no EDID Data. It is recommended to get the proper cable, and not use adapters.
another note: the KMS driver ignores all video settings in config.txt - video mode changes made to this file will have no effect !
however, you can set the resolution manually:
in /boot/cmdline.txt (add to the front/end of the line, NOT a new line)
-- IMPORTANT NOTE: for Bookworm, the file is at /boot/firmware/cmdline.txt !!
video=HDMI-A-1:1024x768@60D
(or whatever resolution you want)
Statistics: Posted by terribleted — Sun Apr 14, 2024 3:35 pm
