[ltp] Dual head with ThinkPad T30, Ubuntu gutsy, xrandr 1.2

[Thomas Hood]

Some months ago I upgraded the Ubuntu OS on my T30 and the unfortunate
result was that I could no longer combine the laptop panel and an external
monitor to display a large desktop.  I had formerly done this by means of
the mergedfb feature of the radeon driver, but this feature was removed.
I recall trying to enable the xinerama feature but I was not successful.

The T30 has an ATI Mobility Radeon 7500 video controller with 16MB.  My
external monitor is a Dell 1704FPVt with dual (VGA/DVI) inputs.  I connect
it to the T30 via the DVI port on a port replicator.

Yesterday I was able to regain my dual-head desktop by doing the following.

* Upgrade to current ubuntu gutsy
* cp /etc/X11/xorg.conf /etc/X11/xorg.conf_PREV
* dpkg-reconfigure xserver-xorg

This generated a new /etc/X11/xorg.conf which I append below.  The file is
shorter than it was before, now omitting fontpath and module-load entries.

* Add to subsection "Display" of section "Screen" in /etc/X11/xorg.conf:

                Virtual         2680 1050

* Reboot

Before I rebooted the laptop display did not work: it repeatedly flashed
and blacked.

After rebooting X started in clone mode; the greeter appeared on both the
laptop panel and on the monitor.

* Log in and wait for panels, etc., to start
* In a terminal window, run

    xrandr --output DVI-0 --right-of LVDS

The desktop then refreshed and spanned both displays.  Running "xrandr -q"
yielded this:

=----------------------------------------------------------
Screen 0: minimum 320 x 200, current 2680 x 1050, maximum 2680 x 1050
VGA-0 disconnected (normal left inverted right)
DVI-0 connected 1280x1024+1400+0 (normal left inverted right) 338mm x 270mm
   1280x1024      60.0*+   75.0     59.9
   1152x864       74.8
   1024x768       75.1     60.0
   800x600        75.0     60.3
   640x480        75.0     60.0
   720x400        70.1
LVDS connected 1400x1050+0+0 (normal left inverted right) 0mm x 0mm
   1400x1050      50.0*+
   1280x800       60.0
   1280x768       60.0
   1024x768       60.0
   800x600        60.3
   640x480        59.9
S-video disconnected (normal left inverted right)
=----------------------------------------------------------

Here is /etc/X11/xorg.conf:

=----------------------------------------------------------
# xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "CoreKeyboard"
        Option          "XkbRules"      "xorg"
        Option          "XkbModel"      "pc104"
        Option          "XkbLayout"     "us"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"                "/dev/input/mice"
        Option          "Protocol"              "ImPS/2"
        Option          "ZAxisMapping"          "4 5"
        Option          "Emulate3Buttons"       "true"
EndSection

Section "InputDevice"
        Identifier      "Synaptics Touchpad"
        Driver          "synaptics"
        Option          "SendCoreEvents"        "true"
        Option          "Device"                "/dev/psaux"
        Option          "Protocol"              "auto-dev"
        Option          "HorizScrollDelta"      "0"
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "stylus"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "stylus"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "eraser"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "eraser"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "InputDevice"
        Driver          "wacom"
        Identifier      "cursor"
        Option          "Device"        "/dev/input/wacom"
        Option          "Type"          "cursor"
        Option          "ForceDevice"   "ISDV4"         # Tablet PC ONLY
EndSection

Section "Device"
        Identifier      "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
        Driver          "ati"
        BusID           "PCI:1:0:0"
EndSection

Section "Monitor"
        Identifier      "Generic Monitor"
        Option          "DPMS"
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
        Monitor         "Generic Monitor"
        DefaultDepth    16
        SubSection "Display"
                Modes           "1400x1050"
                Virtual         2680 1050
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default Layout"
        Screen          "Default Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"

# Uncomment if you have a wacom tablet
#       InputDevice     "stylus"        "SendCoreEvents"
#       InputDevice     "cursor"        "SendCoreEvents"
#       InputDevice     "eraser"        "SendCoreEvents"
        InputDevice     "Synaptics Touchpad"
EndSection
=----------------------------------------------------------

-- 
Thomas Hood