Comment 4 for bug 42731

Revision history for this message
Jiri Bajer (sarimak) wrote : Multihead bug #1

Okay, here's my two cents:

Zaphod is computer serviceman and uses his employer's laptop for daily onsite work. When he returns to the office he plugs his lappie into the docking station (or plugs all the cables manually if his employer saves on equipment) and wants to use external keyboard, mouse and LCD without any interaction (or to switch the location/profile manually at worst). Keyb/mouse work out-of-the box atm but the external LCD doesn't.

To fix it manually (if Zaphod knows how to do it) he has to:
1) find out the resolutions of both laptop's internal LCD and external LCD
2) change /etc/X11/xorg.conf to add MergedFB support using fixed grahic pseudomode computed from both LCD's resloutions
3) restart Xorg to apply the changes
4) use xrandr to switch between single and dual LCD configs

What also works for him then:
1) he is able to switch the configs on-a-fly
2) when he has left some windows on the external LCD and switches to singlehead the windows are migrated to primary screen
3) dragging the windows between the screens works
4) panel is not duplicated on external screen
5) window maximization works even if the screens have got different resolutions
6) SOME applications are dualhead-aware and place the dialogs in the middle of screen (and not the viewport)
7) dualhead works fine with swsusp
8) there is no screen distortion/unused space if the screens have got different resolutions

What doesn't work and annoys him atm:
1) if the external LCD is not connected in the boot time (to be more specific: before Xorg startup) there is no way to switch into the dualhead else than to plug in the VGA cable and restart Xorg
2) he cannot use graphical xrandr front-ends (neither preferences dialog nor systray applet) because they crash when the dualhead mode is selected (and they also display invalid refresh rates - xrandr does this too but doesn't crash)
3) SOME silly-written apps/dialogs still don't care about multihead configurations and assume the middle of the screen = middle of the viewport (and thus place the windows partially on both screens and make their contents almost unreadable) - Hello, Openoffice, did you hear it? ;-)
4) there is no sane rule for new window placement - it depends on screen where is the focused window, screen where is mouse cursor, screen where is the parent window or what?
5) and the obvious one: everything must be configured manually and I'm pretty sure everything won't work for all graphic cards the same way B-(

My observations are based on experience with laptop HP compaq nc6000 (Radeon Mobility 7600, xorg driver) and external LCD HP 1705.

Used SW versions (Dapper):
xserver-xorg 7.0.0-0ubuntu4
xrandr 1.0.1-0ubuntu1
xserver-xorg-driver-ati 6.5.7.3-0ubuntu7

The magical Device section used in Zaphod's /etc/X11/xorg.conf:
Driver "radeon"
Option "DynamicClocks" "true"
Option "MergedFB" "true"
Option "CRT2Position" "RightOf"
Option "Metamodes" "1400x1050-1280x1024 1400x1050"
Option "MergedNonRectangular" "true"