Comment 8 for bug 1880125

comment 33 of bug 1850876 mentions dtoverlay=vc4-fkms-v3d.
i have had that line all along in /boot/firmware/usercfg.txt (which is where it goes on a pi 4).

bug 1850876 references linux-raspi2, and the v2 test kernel is based on linux 5.3.

i'm running ubuntu 20.04 on a pi 4 - the raspi branch - which is based on linux 5.4.

do you have a test kernel built from the raspi branch, or is there a git commit i can check out to build it myself?

i have been successfully building and running kernels from source obtained via:
git clone --depth=1 git://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal -b raspi