Dual GPU system (AMD R5 Vega 11 + RX560)
I'm using a system with a Ryzen R5 3400G APU on a Gigabyte B450 I Aorus motherboard, plus a discrete RX560 GPU. When I have enabled the integrated graphics through BIOS as primary the discrete GPU and integrated graphics works flawlessly on my multiseat (dualhead) system. When I have set discrete GPU as primary integrated graphics not worked at all. Tested on Arch Linux kernel 5.x, 5.6.x.
[ 4.355298] [drm] amdgpu kernel modesetting enabled.
[ 4.357980] amdgpu 0000:0b:00.0: enabling device (0000 -> 0003)
[ 4.375346] amdgpu 0000:0b:00.0: BAR 6: can't assign [??? 0x00000000 flags 0x20000000] (bogus alignment)
[ 4.386257] [drm:amdgpu_get_bios [amdgpu]] *ERROR* Unable to locate a BIOS ROM
[ 4.386260] amdgpu 0000:0b:00.0: Fatal error during GPU init
[ 4.386261] [drm] amdgpu: finishing device.
[ 4.387193] amdgpu: probe of 0000:0b:00.0 failed with error -22