i810/modesetting and Xinerama?

Andreas Schildbach andreas at schildbach.de
Tue Dec 19 15:27:27 PST 2006

Keith Packard wrote:

> Then, you can use xrandr to place the internal screen to the right of
> the external monitor:
> $ xrandr --output LVDS --pos 1920x0 --auto
> This presumes that you've accepted 16bpp as your depth of choice; the
> hardware is limited to 8KB per scanline, so a 32bpp server can only have
> a combined screen width of 2048 pixels.

As you say, I'm getting

~$ xrandr --output LVDS --pos 0x1200 --auto
1920x1968: desired screen size too large

My intention is to put the LVDS beneath the VGA - would my command 
achieve this? How can I reduce color depth to 16 bpp? I already tried 
DefaultDepth 16 in xorg.conf, but it is ignored as is the rest of the 
Screen section.

Just to reconfirm: I managed to run both screens in parallel at 24 bpp 
under Xorg 7.0 / Dapper. However, I was using cinerama which creates two 
well-sized framebuffers rather than one giant buffer that has some 
cut-off if it contains different resolutions, if I understand correctly. 
Will this be an option somewhen? Until then, I guess 16 bpp is adequate.

> xrandr --q12 should list the LVDS panel size as the only mode available
> for that output. However, I note that your BIOS records the panel size
> as 1280x800 while the mode it offers is 1280x768. Which is correct? And
> does xrandr --q12 list both sizes?

I hate Dell and their BIOS-crap )-: The native resolution of the LDVS is 
1280 x 768. Both resolutions are listed, along with several other. I'm 
attaching the output of xrandr --q12.


-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: xrandr.output
URL: <http://lists.x.org/archives/xorg/attachments/20061220/de6d0086/attachment.ksh>

More information about the xorg mailing list