Comment 31 for bug 257941

Created an attachment (id=23102)
Xorg.0.log

Forwarding this bug from a Ubuntu reporter:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/257941

[Problem]
With external monitor splash screen shows scrambled and then when X starts, screen goes black.

[lspci]
01:00.0 VGA compatible controller [0300]: ATI Technologies Inc Radeon Mobility X1400 [1002:7145]

[Original Report]
Using a fresh daily build of Intrepid (tried both the live cd and an installation made with the alternate cd):

Xorg fails when an external monitor is connected to my laptop (Dell Inspiron 6400, ATI X1400 graphics card) through a KVM switch. After a scrambled splash screen, the screen goes black.

The problem does not to occur when the monitor is unplugged or connected to the laptop directly (instead of through the switch). It also works fine in Hardy.

In case it is relevant, this is the KVM switch: http://www.equip-info.net/english/index.php?main=10&gruppe=300&prod=2188
The monitor is a Samsung SyncMaster 930BF.

...later...
With a freshly installed Intrepid (and all upgrades) there has indeed been some development.

X11 still fails, but independently from whether the KVM switch is attached or not. Also, the output from xrandr and get-edid is identical, no matter how the monitor is connected.

Since I'm not sure which two cases you're interested in (I think the KVM switch is no longer the issue), I'm attaching register dumps for all three cases:

*_1screen: no external monitor, everything works

*_2screen: external monitor (directly connected): black screen

*_kvm: external monitor (connected via KVM switch): black screen

Logfiles:

xorg.0.log with ext-Monitor: http://launchpadlibrarian.net/16776933/Xorg.0.log and http://launchpadlibrarian.net/16776938/Xorg.10.log
xorg.0.log with autoconfig: http://launchpadlibrarian.net/17034798/Xorg.0.log
xorg.0.log without Monitor: http://launchpadlibrarian.net/17039647/Xorg.0.log