Problem: DisplayLink in multiple monitors setup

#
# /etc/X11/xorg.d/10-monitor.conf
#
# Current problem: Cannot configure a DisplayLink monitor to act as secondary display.
# Current situation: DisplyLink monitor works alone using xf86-video-driver.
#           If Primary Screen is loaded, X crashes with error:
#           Cannot run in framebuffer mode.  Please specify busIDs for all framebuffer devices
#

# Laptop display
Section "Device"
    Identifier    "Integrated Graphics Controller"
    Driver        "intel"
    BusID     "PCI:0:2:0"
EndSection

Section "Monitor"
    Identifier    "Primary Monitor"
EndSection

Section "Screen"
    Identifier    "Internal Screen"
    Device        "Integrated Graphics Controller"
    Monitor       "Primary Monitor"
    DefaultDepth  16
    SubSection "Display"
        Depth     16
        Modes     "1366x768"
    Virtual   2732 768
    EndSubSection
EndSection

# External display
Section "Device"
    Identifier    "DisplayLink"
    Driver    "fbdev"
    BusID     "USB"
    Option    "fbdev" "/dev/fb1"
EndSection

Section "Monitor"
    Identifier    "Secondary Monitor"
EndSection

Section "Screen"
    Identifier    "External Screen"
    Device        "DisplayLink"
    Monitor       "Secondary Monitor"
    DefaultDepth  16
    EndSubSection
EndSection

# Dual Monitor configuration
Section "ServerLayout"
    Identifier  "DualScreen"
    Screen  "External Screen"
#    Screen "Internal Screen" LeftOf "External Screen" # Uncomment this and get an error.
EndSection