Colin Charles Agenda

Dual-display with the Intel 945GM on Gutsy Gibbon?

Resisting an upgrade, is hard, so I finished some work on Friday, and proposed to upgrade away to Gutsy Gibbon. I’ll talk about what I like and don’t later, but I still face a problem. I can’t seem to get X/xrandr working as well as I’d like it to. I also can’t get all the desktop effect bling going, but that is not as significant a problem as working VGA out.

lspci says, I have a Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03). I drive my laptop at 1440×900, and externally, I’ve got a 17″ LCD panel that can go 1280×1024 (FWIW, I tested against an external 19″ wide panel capable of 1440×900, but it made no difference). However, xrandr thinks I can only, at most, display 1440×1440, and I think that’s why I’m not being able to get a nice “stretch screen” (i.e. two desktops, not mirrored displays) experience going.

xrandr -q
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1440 x 1440
VGA connected (normal left inverted right)
1280x1024 59.9
640x480 60.0
LVDS connected 1440x900+0+0 (normal left inverted right) 303mm x 190mm
1440x900 60.0*+
1280x800 60.0
1280x768 60.0
1024x768 60.0
800x600 60.3
640x480 59.9
TV disconnected (normal left inverted right)

So, mirroring works. My desktop looks a little shitty, but at 1280×1024, all is well and dandy. I have a feeling that when I plug it into an LCD projector, I might get away with things working, for a change. That alone, is impressive. So, how do I magically get a dual-display, stretched desktop experience? My xorg.conf file for reference, is tacked to the end of this.

My heart goes out to whomever decided to write displayconfig-gtk. This is a step in the right direction. End-users will want a GUI to choose external displays and stuff. I love the idea of location profiles (so, at home, maybe I’m tacked to an external 1280×1024 monitor, at another location maybe another, a roaming locating that just creates a 800×600 display, etc.). Of course, it would help if this utility actually worked. It doesn’t, and is currently broken, from my experience with it. Why is it included, under the guise like it might work?

Kudos to Intel, and their page on How to setup Dual Head for Intel Graphics with RandR 1.2. Everyone says, stick to Intel and you won’t go wrong with Linux. Why then, does such a page need to exist? Why is my out-of-the-box experience, still so bad?

If it helps, here’s the xorg.conf configuration file (I didn’t muck with it, its dpkg configured). Help appreciated, and remind me to buy you a beer when/if I see you next.

Section "Files"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
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 "HorizEdgeScroll" "0"
EndSection

Section "InputDevice"
Driver "wacom"
Identifier "stylus"
Option "Device" "/dev/input/wacom"
Option "Type" "stylus"
EndSection

Section "InputDevice"
Driver "wacom"
Identifier "eraser"
Option "Device" "/dev/input/wacom"
Option "Type" "eraser"
EndSection

Section "InputDevice"
Driver "wacom"
Identifier "cursor"
Option "Device" "/dev/input/wacom"
Option "Type" "cursor"
EndSection

Section "Device"
Identifier "Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller"
Driver "intel"
BusID "PCI:0:2:0"
VideoRam 65536
EndSection

Section "Monitor"
Identifier "Generic Monitor"
Option "DPMS"
HorizSync 28-72
VertRefresh 43-60
EndSection

Section "Screen"
Identifier "Default Screen"
Device "Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller"
Monitor "Generic Monitor"
DefaultDepth 24
SubSection "Display"
Modes "1440x900"
EndSubSection
EndSection

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

InputDevice "Synaptics Touchpad"
EndSection

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