Dual head on ATI FirePro M5800

[Ole Tange]

I am trying to get dual head on ATI FirePro M5800 working. LVDS works,
but VGA-0 is in power save mode no matter what I do.

My colleague got the non-free driver working, but I would prefer using
the free driver. My research seems to indicate the chipset is called
Redwood or r8xx or RV830 or r800 or Evergreen - but I could be wrong.

I have been unable to find a guide for this card and the obvious
(xrandr --output LVDS --output VGA-0 --left-of LVDS) does not work.
Neither does KDE's gui config of display.

Below is some output that may help.

/Ole

$ lspci |grep VGA
01:00.0 VGA compatible controller: ATI Technologies Inc Device 68c0

$ cat /etc/X11/xorg.conf
Section "Screen"
       Identifier      "Configured Screen Device"
       Device  "Configured Video Device"
       SubSection "Display"
               Virtual 3280 1080
       EndSubSection
EndSection

Section "Device"
       Identifier      "Configured Video Device"
EndSection

$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 3280 x 1080
LVDS connected 1920x1080+0+0 (normal left inverted right x axis y
axis) 0mm x 0mm
  1920x1080      59.9*+
  1680x1050      60.0
  1600x1024      60.2
  1400x1050      60.0     60.0
  1280x1024      59.9     60.0
  1440x900       59.9     59.9
  1280x960       60.0     59.9
  1280x854       59.9
  1360x768       59.8
  1280x800       59.8
  1152x864       60.0
  1280x720       59.9
  1152x768       59.8
  1024x768       60.0     59.9
  800x600        60.3     59.9
  640x480        59.9     59.4
DisplayPort-2 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
VGA-0 connected (normal left inverted right x axis y axis)
  1360x768       59.8
  1152x864       60.0
  1024x768       60.0
  800x600        60.3
  640x480        59.9