Bug#492457: Regression: Dual head screen size detection broken after upgrade

Alex Deucher alexdeucher at gmail.com
Sat Jul 26 10:55:20 PDT 2008

On Sat, Jul 26, 2008 at 5:21 AM, Tobias Diedrich
<ranma+debianbts at tdiedrich.de> wrote:
> Package: xserver-xorg-video-ati
> Version: 1:6.9.0-1+lenny1
> Severity: normal
> Hash: SHA1
> Setup:
> Dual-head with single card (Radeon X300), two TFTs with different native
> resolution (SyncMaster 215TW 1680x1050 and Flatron L2010P 1600x1200).
> Tuesday my harddrive died and I had to restore from backup (march).
> Normally I don't safe-upgrade/dist-upgrade as often as I probably
> should, so I'm not sure which exact version of xorg I had prior to the
> harddrive failure, but it should have been a version somewhere between
> the march version and the current version I guess. :)
> After restoring from backup and safe-upgrade/dist-upgrade, my dual-head
> setup is broken:
> When I now start X, the SyncMaster 215TW (1680x1050 native resolution) is
> configured with 1600x1200 instead.  Previously this was correctly
> configured to 1680x1050.
> However this only happens if both monitors are connected.
> With just the SyncMaster 215TW attached it is correctly configured for
> 1680x1050.
> Running "xrandr --output DVI-1 --auto" later will fix this and change
> the output to the native panel resolution.

This is probably due to a change in default xrandr mode selection
policy in the two xserver versions you are using.

> (However fluxbox still thinks the desktop is 1600x1200, for example when
> maximizing windows, but I suspect this is a fluxbox bug?)

Since you are using a clone mode, fluxbox is getting it's geometry
from the 1600x1200 screen.

> As you can see, two DVI-ports are detected even though only one is
> really present on the card.
> The SyncMaster is connected to the DVI port and the Flatron is connected
> to the VGA port.  The S-Video port is present, but unused.

Please send me your video bios and the pci subsystem ids for your
video card, and I'll fix this issue.

subsystem ids:
lspci -nv

video bios (as root), use lspci to get the pci slot id:
cd /sys/bus/pci/devices/<pci slot id>/
echo 1 > rom
cat rom > /tmp/videocard.rom
echo 0 > rom


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