Comment # 5 on bug 110637 from Alexander Mezin

And BTW with kernel 4.19.40 and latest git firmware
(https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/commit/?id=2579167548be33afb1fe2a9a5c141561ee5a8bbe)
monitors switch off on boot as soon as amdgpu driver loads and never turn on
again