https://bugzilla.kernel.org/show_bug.cgi?id=210263
--- Comment #5 from Fabian (fabiscafe@mailbox.org) --- As of Kernel 5.15, I don't need fbcon=nodefer anymore. By default the backlight works and is set on start. I still get from time to time an boot-error by systemd, but that can be also worked around by loading amdgpu early.
Can someone confirm this?