Arch Linux

tmahring

Member

Registered: 2014-12-06

Posts: 1

Multihead - Multiheadache... displaymanager messes up xrandr

Hi guys
I have been messing around with my X config for a few days now, it would be great is anyone of you has an idea on how to fix it.

Here is my setup:
2 Graphics gards: 1st one is an NVIDA gtx 770, 2nd one is an AMD Radeon HD 6450
4 Displays connected. left one to the radeon, the other three to the nvidia card.

I'm using the proprietary Nvidia drivers + the open source radeon drivers (i need 3d acceleration on my main display which is connected to the nvidia card, the rest don't really matter)

I can get my displays set up correctly using xrandr in my .xinitrc:

xrandr --setprovideroutputsource 1 0
xrandr --output DVI-I-1 --mode 1920x1080 --primary --pos 0x0 --output DVI-1-0 --mode 1280x1024 --pos -1280x0 --output DVI-D-0 --mode 1280x1024 --pos 1940x0 --output HDMI-0 --mode 1920x1080 --pos 3220x0

So everything works fine as long is log into the console and start x via startx.

However, as soon as i try using a display manager (i have tried gdm, lxdm and lightdm so far) the display on the radeon card stays black.

xrandr --listproviders

also only shows the nvidia card. (it shows both cards when using startx)

here is my xorg.conf:

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    Screen      1  "Screen1"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusID          "PCI:1:0:0"
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "radeon"
    VendorName     "AMD Corporation"
    BusID          "PCI:2:0:0"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Option "AllowEmptyInitialConfiguration"
EndSection

Section "Screen"
    Identifier     "Screen1"
    Device         "Device1"
    Option "AllowEmptyInitialConfiguration"
EndSection

Any advice would be greatly appreciated.