Bug#488277: xserver-xorg-video-radeon: No longer uses correct resolution when a second screen is connected

[Torquil Macdonald Sørensen]

On Saturday 28 June 2008 01:11:51 Alex Deucher wrote:
> On Fri, Jun 27, 2008 at 10:35 AM, Torquil Macdonald Sørensen
>
> <torquil at gmail.com> wrote:
> > Package: xserver-xorg-video-radeon
> > Version: 1:6.8.192-1
> > Severity: normal
> >
> > Up until the last few days, when I started my laptop (1400x1050) with an
> > external screen (LCD 1280x1024), X would automatically lower the
> > resolution so that it was appropriate for the external screen, instead of
> > the 1400x1050 it normally uses on my laptop (IBM T24 with ATI Radeon
> > Mobility 9600). It doesn't do that any more.
>
> This is an xserver change.
>
> > Now I get a cropped 1400x1050 on the external LCD instead. E.g. I can
> > only see the upper half of the KDE panel on the external screen. The
> > lowest part of the desktop is not shown.
>
> The xserver mode default mode chooser has changed.  Nothing to do with
> the driver.  removing the "Modes" line from your config may fix it:
> Modes "1400x1050" "1280x1024" "1280x960" "1024x768" "800x600"
> "700x525" "640x480"

Removing the Modes line (in fact I removed DefaultDepth + Entire "Display" 
subsection from the Screen Section) had no effect on this.

> > When I try to lower the resolution to 1280x1024 using kcontrol, the
> > external screen becomes black and a 1280x1024 image is shown only on the
> > laptop screen.
>
> kcrontrol is probably not xrandr 1.2 compliant and probably uses the
> old xrandr 1.0 API which only affect one of the outputs and leads to
> problems on multi-head systems.

Ok, maybe kcontrol isn't up to the job, I have heard before that it does not 
support xrandr 1.2. I tried to use xrandr manually to change the desktop size 
using xrandr with --mode and --output options. I managed to get a 1280x1024 
resolution on the laptop screen after putting the "Modes" line back into 
xorg.conf (otherwise 1280x1024 was not listed as a mode for the LVDS). But 
the desktop image was cropped at the bottom on both screens. I did not manage 
to get a 1280x1024 "desktop geometry" to correspond to the 1280x1024 screen 
resolutions on the LVDS and external screen. But I will do some more 
investigating on how the xrandr command works, I guess there is some way to 
do it.

Thanks,
Torquil Sørensen