Comment # 4 on bug 1106577 from Joe Morris

It is weird that the first boot after updating both the 4.18.0 and 4.18.5
kernel worked. Maybe that is why the LiveCD KDE works, since it is read only. I
can't figure out why /dev/dri/card0 must work once, but not until the kernel is
changed once again will it work again. It is a consistent hard failure, but
journalctl has been no help, and it is hard to debug as the screen is locked at
the kde splash screen, keyboard no longer works, but if I just boot and
shutdown from the sddm login, it will shutdown OK. I can ssh into my laptop and
get some info if anyone has any idea what to check. I can use my laptop with
the last 4.17.14 kernel installed, so all other than the kernel packages seem
to work. I suspect xf86-video-amdgpu incompatibility with the >4.18.0 kernel,
since the kernel makes it to the sddm login screen and can still shutdown from
there like normal. Any ideas are appreciated.