У меня есть три дисплея, подключенных через DVI на двух разных картах ATI в Arch Linux с использованием xf86-video-ati .
Все три в настоящее время обслуживают вывод, но один из моих дисплеев (тот, что на второй карте) возвращается к серому экрану и черному курсору "х" после входа в GDM.
Стоит отметить, что дисплей работает на экране входа в систему GDM, отображая фон экрана входа в систему (но не поле входа в систему, как это делают два других дисплея).
Как получить рабочий стол со всеми тремя дисплеями?
Я использую GDM и Gnome3 со следующим xorg.conf:
Section "ServerLayout"
    Identifier     "X.org Configured"
    Screen      0  "Screen0" 0 0
    Screen      1  "Screen1" RightOf "Screen0"
    Screen      2  "Screen2" RightOf "Screen1"
    Screen      3  "Screen3" RightOf "Screen2"
    InputDevice    "Mouse0" "CorePointer"
    InputDevice    "Keyboard0" "CoreKeyboard"
EndSection
Section "Files"
    ModulePath   "/usr/lib/xorg/modules"
    FontPath     "/usr/share/fonts/misc/"
    FontPath     "/usr/share/fonts/TTF/"
    FontPath     "/usr/share/fonts/OTF/"
    FontPath     "/usr/share/fonts/Type1/"
    FontPath     "/usr/share/fonts/100dpi/"
    FontPath     "/usr/share/fonts/75dpi/"
EndSection
Section "Module"
    Load  "glx"
EndSection
Section "InputDevice"
    Identifier  "Keyboard0"
    Driver      "kbd"
EndSection
Section "InputDevice"
    Identifier  "Mouse0"
    Driver      "mouse"
    Option      "Protocol" "auto"
    Option      "Device" "/dev/input/mice"
    Option      "ZAxisMapping" "4 5 6 7"
EndSection
Section "Monitor"
    Identifier   "Monitor0"
    VendorName   "Monitor Vendor"
    ModelName    "Monitor Model"
EndSection
Section "Monitor"
    Identifier   "Monitor1"
    VendorName   "Monitor Vendor"
    ModelName    "Monitor Model"
EndSection
Section "Monitor"
    Identifier   "Monitor2"
    VendorName   "Monitor Vendor"
    ModelName    "Monitor Model"
EndSection
Section "Monitor"
    Identifier   "Monitor3"
    VendorName   "Monitor Vendor"
    ModelName    "Monitor Model"
EndSection
Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "NoAccel"               # [<bool>]
        #Option     "SWcursor"              # [<bool>]
        #Option     "EnablePageFlip"        # [<bool>]
        #Option     "ColorTiling"           # [<bool>]
        #Option     "ColorTiling2D"         # [<bool>]
        #Option     "RenderAccel"           # [<bool>]
        #Option     "SubPixelOrder"         # [<str>]
        #Option     "AccelMethod"           # <str>
        #Option     "EXAVSync"              # [<bool>]
        #Option     "EXAPixmaps"            # [<bool>]
        #Option     "ZaphodHeads"           # <str>
        #Option     "EnablePageFlip"        # [<bool>]
        #Option     "SwapbuffersWait"       # [<bool>]
    Identifier  "Card0"
    Driver      "radeon"
    BusID       "PCI:3:0:0"
EndSection
Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "NoAccel"               # [<bool>]
        #Option     "SWcursor"              # [<bool>]
        #Option     "EnablePageFlip"        # [<bool>]
        #Option     "ColorTiling"           # [<bool>]
        #Option     "ColorTiling2D"         # [<bool>]
        #Option     "RenderAccel"           # [<bool>]
        #Option     "SubPixelOrder"         # [<str>]
        #Option     "AccelMethod"           # <str>
        #Option     "EXAVSync"              # [<bool>]
        #Option     "EXAPixmaps"            # [<bool>]
        #Option     "ZaphodHeads"           # <str>
        #Option     "EnablePageFlip"        # [<bool>]
        #Option     "SwapbuffersWait"       # [<bool>]
    Identifier  "Card1"
    Driver      "radeon"
    BusID       "PCI:4:0:0"
EndSection
Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "ShadowFB"              # [<bool>]
        #Option     "DefaultRefresh"        # [<bool>]
        #Option     "ModeSetClearScreen"    # [<bool>]
    Identifier  "Card2"
    Driver      "vesa"
    BusID       "PCI:3:0:0"
EndSection
Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "ShadowFB"              # [<bool>]
        #Option     "DefaultRefresh"        # [<bool>]
        #Option     "ModeSetClearScreen"    # [<bool>]
    Identifier  "Card3"
    Driver      "vesa"
    BusID       "PCI:4:0:0"
EndSection
Section "Screen"
    Identifier "Screen0"
    Device     "Card0"
    Monitor    "Monitor0"
    SubSection "Display"
        Viewport   0 0
        Depth     1
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     4
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     8
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     15
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     16
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     24
    EndSubSection
EndSection
Section "Screen"
    Identifier "Screen1"
    Device     "Card1"
    Monitor    "Monitor1"
    SubSection "Display"
        Viewport   0 0
        Depth     1
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     4
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     8
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     15
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     16
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     24
    EndSubSection
EndSection
Section "Screen"
    Identifier "Screen2"
    Device     "Card2"
    Monitor    "Monitor2"
    SubSection "Display"
        Viewport   0 0
        Depth     1
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     4
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     8
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     15
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     16
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     24
    EndSubSection
EndSection
Section "Screen"
    Identifier "Screen3"
    Device     "Card3"
    Monitor    "Monitor3"
    SubSection "Display"
        Viewport   0 0
        Depth     1
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     4
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     8
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     15
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     16
    EndSubSection
    SubSection "Display"
        Viewport   0 0
        Depth     24
    EndSubSection
EndSection
