I have a probleme, I had changed the dtoverlay=vc4-kms-v3d to dtoverlay=vc4-fkms-v3d but now I would like use kms but when I change my dtoverlay to kms, they don't boot;I try to reinstall raspbian os (32 bits and 64 bits) and that's no work ; Can you help me please Thanks
I noticed this question because I too am having problems with the KMS drivers. I’m very new to learning about the Raspeberri Pi, so I can’t actually be of real help regarding the drivers, but one thing I noticed when changing from FKMS to KMS is that the Pi is actually booting, it’s just not diaplaying on the monitor. Apparently it has something to do with the hdmi system.
I noticed this because I was using VNC one time when rebooting after changing from fkms to kms. The remote computer connected up with the Pi automatically when it booted, but the monitor the Pi was connected to went blank.
Things I tried which got the screen to display (one of these - or both - i don’t actually know for sure); uncomment the “hdmi_force_hotplug=1”, and “config_hdmi_boost=4” lines in the config.txt file.
This got my display to show and was working well, for a while. Of course, something else went wrong and now I’m back to using the FKMS drivers.
I’m not sure the coding is really ready for prime time here. I’m trying to use the newest, most up to date Pi hardware and software (64bit, Bullseye, on a 4b and a Zero 2W) but the older deprecated code (FKMS drivers for example) appears to work much better and quicker than the newer code.
I’ve also noticed from my searches that this driver issue has been a problem for a couple of years already. So, there’s no knowing when it may ever be ready. Maybe when the Pi-5 comes out they’ll have the 64-bit code ready.
Hopefully someone else with more knowledge will chime in here and help us out.