xrandr shows two displays (LVDS1), but how can I use VGA1 only?

Question

We're running Ubuntu 11 on this hardware: Foxconn R20-D2 Intel Atom D510 Intel NM10 Intel GMA 3150 Barebone

There is no integrated display (it is a barebone box). I connected an external VGA to it.

However xrandr shows two displays:

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096

LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768       60.0*+
   800x600        60.3     56.2  
   640x480        59.9  

VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200      60.0 +
   1600x1200      60.0  
   1680x1050      60.0  
   1280x1024      76.0     75.0     72.0     60.0  
   1440x900       75.0     59.9  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0* 
   832x624        74.6  
   800x600        72.2     75.0     60.3  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  

But I don't have two displays. How can I get rid of LVDS1 and use only VGA1?

The direct result is that I'm seeing a 1024x768 resolution on my VGA display, because the OS is using "mirror" mode which uses the lower resolution of the two. Turning off the mirror is not a solution. I want to fix it.

Related logs:

...

[    20.019] (II) intel(0): Creating default Display subsection in Screen section
        "Default Screen Section" for depth/fbbpp 24/32
[    20.019] (==) intel(0): Depth 24, (--) framebuffer bpp 32
[    20.019] (==) intel(0): RGB weight 888
[    20.019] (==) intel(0): Default visual is TrueColor
[    20.019] (II) intel(0): Integrated Graphics Chipset: Intel(R) Pineview G
[    20.019] (--) intel(0): Chipset: "Pineview G"
[    20.019] (**) intel(0): Relaxed fencing enabled
[    20.019] (**) intel(0): Wait on SwapBuffers? enabled
[    20.019] (**) intel(0): Triple buffering? enabled
[    20.019] (**) intel(0): Framebuffer tiled
[    20.019] (**) intel(0): Pixmaps tiled
[    20.020] (**) intel(0): 3D buffers tiled
[    20.020] (**) intel(0): SwapBuffers wait enabled
[    20.020] (==) intel(0): video overlay key set to 0x101fe
[    20.020] (II) intel(0): Output LVDS1 has no monitor section
[    20.020] (II) intel(0): found backlight control interface /sys/class/backlight/intel_backlight
[    20.080] (II) intel(0): Output VGA1 has no monitor section
[    20.080] (II) intel(0): EDID for output LVDS1
[    20.081] (II) intel(0): Not using default mode "320x240" (doublescan mode not supported)
[    20.081] (II) intel(0): Not using default mode "400x300" (doublescan mode not supported)
[    20.081] (II) intel(0): Not using default mode "400x300" (doublescan mode not supported)
[    20.081] (II) intel(0): Not using default mode "512x384" (doublescan mode not supported)
...
[    20.082] (II) intel(0): Not using default mode "960x600" (doublescan mode not supported)
[    20.082] (II) intel(0): Printing probed modes for output LVDS1
[    20.082] (II) intel(0): Modeline "1024x768"x60.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz)
[    20.082] (II) intel(0): Modeline "800x600"x60.3   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz)
[    20.082] (II) intel(0): Modeline "800x600"x56.2   36.00  800 824 896 1024  600 601 603 625 +hsync +vsync (35.2 kHz)
[    20.082] (II) intel(0): Modeline "640x480"x59.9   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz)
[    20.149] (II) intel(0): EDID for output VGA1
[    20.149] (II) intel(0): Manufacturer: BNQ  Model: 771b  Serial#: 6595
[    20.149] (II) intel(0): Year: 2008  Week: 16
[    20.149] (II) intel(0): EDID Version: 1.3
[    20.149] (II) intel(0): Analog Display Input,  Input Voltage Level: 0.700/0.700 V

...
[    20.152] (II) intel(0): Modeline "640x480"x60.0   25.20  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz)
[    20.152] (II) intel(0): Modeline "720x400"x70.1   28.32  720 738 846 900  400 412 414 449 -hsync +vsync (31.5 kHz)
[    20.152] (II) intel(0): Output LVDS1 connected
[    20.152] (II) intel(0): Output VGA1 connected
[    20.152] (II) intel(0): Using exact sizes for initial modes
[    20.152] (II) intel(0): Output LVDS1 using initial mode 1024x768
[    20.152] (II) intel(0): Output VGA1 using initial mode 1024x768
[    20.152] (II) intel(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated.


...

Answer 1

Try this in terminal:

xrandr --output LVDS1 --off 
xrandr --output VGA1 --mode 1920x1200

If that does the trick, there are a few ways to make it persistent. One is to just create a startup script or GDM script that makes these changes at log on. The other option would be to craft a custom xorg.conf, however I don't know how these things work with more recent releases of Ubuntu. I know they've done a bunch to muck with the DE and whatnot.

The ArchLinux wiki discusses this some. I know you're on Ubuntu, but this info should be pretty much universal: https://wiki.archlinux.org/index.php/Xrandr

Answer 2

I've just encountered the problem. I'm using CentOS 6.3 on a Foxconn RD20-D2. You can see my bug report in Red Hat Bugzilla 872870.

The simplest fix is to change /boot/grub/grub.conf (or the equivalent), adding "video=LVDS-1:d" to the kernel parameters.