Re: xorg problem--dual-head, Debian vs. Ubuntu

[debian@waysoft.com]

On Mon, 15 Mar 2010 09:53:48 -0400
Jesse Sheidlower <jester@panix.com> wrote:

> 
> Hi. I'm running Debian unstable on a Lenovo T60. I'd like to
> run this dual-head with an external monitor, but have been
> having some problems that I tried to solve but eventually gave
> up on because I'm so lousy with X configuration. However, I
> recently discovered that things work fine out-of-the-box with
> Ubuntu 9.10, running on the same computer (via a live USB
> stick). So I'm wondering if there's some way to figure out why
> there's a difference, and whether I can get the Debian system
> working in the same way.
> 
> The T60 has a Radeon X1300 card; the built-in monitor runs at
> 1400 x 1050. I'm trying to attach a 1280 x 1024 external
> monitor through the VGA port. I'm running Xorg 1.7.5, and I do
> not have an xorg.conf at all, I'm letting Xorg generate the
> configuration. When I plug in the external monitor, and run
> Display Preferences to try to set up the two displays, I get a
> popup message reading "The selected configuration for displays
> could not be applied[:] required virtual size does not fit
> available size: requested=(2680,1050), minimum=(320, 200),
> maximum=(1400, 1400)".
> 
> I've Googled this and found a few bug reports that don't,
> however, clarify what's going on.
> 
> But the notable thing for me is that running Ubuntu 9.10,
> which is running Xorg 1.6.4, this Just Works, with everything
> else identical--same hardware, same lack of xorg.conf file,
> etc.
> 
> I'd be grateful for any suggestions. I'd vastly prefer _not_
> to have to start messing around with the configuration file,
> because apart from this one issue, I don't seem to need one,
> and Ubuntu doesn't seem to need it either.
> 
> Thanks.
> 
> Jesse Sheidlower

> 

There may be some way to do this without an xorg.conf, but I'm not
familiar with it.  A simple conf, like the following, might work, though, and is pretty simple to try...

Section "ServerLayout"
        Identifier     "dual head configuration"
        Screen          0       "Screen0" 0 0
EndSection

Section "Device"
        Identifier      "Videocard0"
        Option          "monitor-VGA1" "monitor1"
        Option          "monitor-VGA2" "monitor2"
EndSection

Section "Monitor"
        Identifier      "monitor1"
        Option          "Position" "0 0"
        Option          "DPMS" "true"
EndSection

Section "Monitor"
        Identifier      "monitor2"
        Option          "RightOf" "monitor1"
        Option          "DPMS" "true"
EndSection

Section "Screen"
        Identifier      "Screen0"
        Device          "Videocard0"
        DefaultDepth    24
        SubSection "Display"
                Virtual 2680 1050
        EndSubSection
EndSection

The trickiest part of this is determining the screen names (VGA1 and
VGA2 in my example).  To find yours, run xrandr (as normal user, not
root) and look for the lines like "xxxx connected 1400x1050" for each
screen - the xxxx's are what you're looking for.

Yep... Ubuntu does a number things "under the covers."  Some folks love
this, some not so much.

jeff