no window manager on second screen for dual head mode

[Jammy Zhou]

If enable dual head mode (two X screens) on Ubuntu 11.10, there is no window manager on second screen after login (no window decoration, cannot move/resize window, cursor shown as "X" instead of arrow, ...). And the unity launcher and panel doesn't show on second screen either.

lsb_release -rd
Description: Ubuntu 11.10
Release: 11.10

apt-cache policy compiz
compiz:
  Installed: 1:0.9.6+bzr20110929-0ubuntu5
  Candidate: 1:0.9.6+bzr20110929-0ubuntu5
  Version table:
 *** 1:0.9.6+bzr20110929-0ubuntu5 0
        500 http://cn.archive.ubuntu.com/ubuntu/ oneiric-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1:0.9.6+bzr20110929-0ubuntu3 0
        500 http://cn.archive.ubuntu.com/ubuntu/ oneiric/main amd64 Packages

There is another problem for nautilus in this dual head configuration.
https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/885989

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Michael Casadevall (mcasadevall)]

Marking as incomplete as this is for 11.10, and no confirmation ont his bug.

[Eduard Hasenleithner (eduard-hasenleithner)]

I am seeing the same problem with 12.04. Configuring with TwinView (i.e. one large desktop on both monitors) works, but configuring for "Separate X screen" exhibits the problem described in the bug report.

[James M. Leddy (jm-leddy)]

Hi Jammy, and Eduard,

Is "Separate X screens" meaning two different X displays a la Xinerama? That has been unsupported in the distro for a while now since xrandr is now the preferred way to get this functionality.

[Jammy Zhou (jammy-zhou)]

James, for "separate X screens", there are more than one screen sections in xorg.conf, and each screen has dedicated displays. In this configuration, windows cannot be moved from one screen to another. Xinerama is based on "separate X screens", but it is not necessary.

[Launchpad Janitor (janitor)]

[Expired for compiz (Ubuntu) because there has been no activity for 60 days.]

[James M. Leddy (jm-leddy)]

Hi Jammy, Please provide a sample xorg.conf that is configured as you mentioned in comment #5.

[Jammy Zhou (jammy-zhou)]

Hi James,
I think this is a generic issue for all platforms. With AMD graphics card and fglrx driver, this problem can be easily reproduced with steps below:
- connect two monitors to the graphics card
- install the fglrx driver
- run aticonfig --initial=dual-head -f (two screen sections will be specified in xorg.conf)
- restart X
- there is no window manager on the second screen, and the display is totally white for the second screen (LP#885989, this issue can be workarounded by kill the nautilus process)

BTW, "DISPLAY=:0.1 compiz &" can be used to launch compiz on the second screen.

[James M. Leddy (jm-leddy)]

Moving to confirmed based on previous comment.

[James M. Leddy (jm-leddy)]

I'm unable to reproduce this bug, as well as bug 885989. The seccond screen in xorg.conf does not appear to work (see Xorg.0.log). I do have dual (physical) screens working great via xrandr and gnome-settings daemon. This is using fglrx-updates-12.104-0ubuntu0.0.1 and kernel 3.2 in precise.

Here are the relevent sections of Xorg.0.log

[ 15.802] (==) Log file: "/var/log/Xorg.0.log", Time: Wed Oct 16 16:02:06 2013
[ 15.802] (==) Using config file: "/etc/X11/xorg.conf"
[ 15.802] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[ 15.944] (==) ServerLayout "aticonfig Layout"
[ 15.944] (**) |-->Screen "aticonfig-Screen[0]-0" (0)
[ 15.944] (**) | |-->Monitor "aticonfig-Monitor[0]-0"
[ 15.944] (**) | |-->Device "aticonfig-Device[0]-0"
[ 15.944] (**) |-->Screen "aticonfig-Screen[0]-1" (1)
[ 15.944] (**) | |-->Monitor "aticonfig-Monitor[0]-1"
[ 15.944] (**) | |-->Device "aticonfig-Device[0]-1"

and

[ 17.046] (EE) Screen 2 deleted because of no matching config section.