I have two GPUs in my desktop computer, Radeon VII and a Radeon R7.
$ lspci -knn | grep -iA3 VGA
05:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Oland PRO [Radeon R7 240/340 / Radeon 520] [1002:6613]
Subsystem: PC Partner Limited / Sapphire Technology Oland PRO [Radeon R7 240/340] [174b:e263]
Kernel driver in use: radeon
Kernel modules: radeon, amdgpu
--
0d:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Vega 20 [Radeon VII] [1002:66af] (rev c1)
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Vega 20 [Radeon VII] [1002:081e]
Kernel driver in use: amdgpu
Kernel modules: amdgpu
Configured both in xorg.conf
like this -
Section "ServerLayout"
Identifier "Layout0"
Screen "Screen0" 0 1440
Screen "Screen1" 2560 1440
Screen "Screen2" 0 0
Screen "Screen3" 2560 0
Screen "Screen4"
Screen "Screen5"
Option "Xinerama" "false"
EndSection
Section "Monitor"
Identifier "HDMI-A-1"
Option "Primary" "true"
EndSection
Section "Monitor"
Identifier "DisplayPort-0"
EndSection
Section "Monitor"
Identifier "DisplayPort-1"
EndSection
Section "Monitor"
Identifier "DisplayPort-2"
EndSection
Section "Monitor"
Identifier "HDMI-A-0"
EndSection
Section "Monitor"
Identifier "DVI-D-0"
EndSection
Section "Device"
Identifier "Card0"
Driver "amdgpu"
BusID "PCI:13:0:0"
EndSection
Section "Device"
Identifier "Card1"
Driver "amdgpu"
BusID "PCI:13:0:0"
EndSection
Section "Device"
Identifier "Card2"
Driver "amdgpu"
BusID "PCI:13:0:0"
EndSection
Section "Device"
Identifier "Card3"
Driver "amdgpu"
BusID "PCI:13:0:0"
EndSection
Section "Device"
Identifier "Card4"
Driver "radeon"
BusID "PCI:05:0:0"
EndSection
Section "Device"
Identifier "Card5"
Driver "radeon"
BusID "PCI:05:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "HDMI-A-1"
EndSection
Section "Screen"
Identifier "Screen1"
Device "Card1"
Monitor "DisplayPort-0"
EndSection
Section "Screen"
Identifier "Screen2"
Device "Card2"
Monitor "DisplayPort-1"
EndSection
Section "Screen"
Identifier "Screen3"
Device "Card3"
Monitor "DisplayPort-2"
EndSection
Section "Screen"
Identifier "Screen4"
Device "Card4"
Monitor "HDMI-A-0"
EndSection
Section "Screen"
Identifier "Screen5"
Device "Card5"
Monitor "DVI-D-0"
EndSection
The problem I am having is that the two GPUs created two separate screens, and I cannot move with the mouse from one screen to the other.
Another problem is that when the second GPU is removed from configuration, the Vega II allows my window manager to recognize the 4 monitors connected as separate displays. But when both the GPUs are configured as working, the window manager recognizes each one of them as a separate display.
These commands shed more light on the problem:
$ xrandr --listproviders --listmonitors
Providers: number : 1
Provider 0: id: 0x58 cap: 0x9, Source Output, Sink Offload crtcs: 6 outputs: 4 associated providers: 0 name:AMD Radeon VII @ pci:0000:0d:00.0
Monitors: 4
0: +*HDMI-A-1 2560/597x1440/336+0+1440 HDMI-A-1
1: +DisplayPort-0 2560/597x1440/336+2560+1440 DisplayPort-0
2: +DisplayPort-1 2560/597x1440/336+0+0 DisplayPort-1
3: +DisplayPort-2 2560/597x1440/336+2560+0 DisplayPort-2
$ DISPLAY=:0.1 xrandr --listproviders --listmonitors
Providers: number : 1
Provider 0: id: 0xb5 cap: 0x9, Source Output, Sink Offload crtcs: 2 outputs: 3 associated providers: 0 name:OLAND @ pci:0000:05:00.0
Monitors: 1
0: +*HDMI-0 1280/527x1024/296+0+0 HDMI-0
Why is the second GPU receiving a separate screen instead of added as another monitor to the same screen as the first 4 monitors on the first GPU?
Full Xorg log of this split setup at https://gist.github.com/kesor/217daebf0ffbd58c70e2b9ec3a9c8ea6