[ltp] External monitor

Carlos Moffat linux-thinkpad@linux-thinkpad.org
Wed, 29 Nov 2006 11:02:56 -0500


On Wed, 2006-11-29 at 16:51 +0200, Marius Gedminas wrote:
> On Wed, Nov 29, 2006 at 11:07:48AM +0100, credito@gmx.de wrote:
> > I have a T42 with Debian unstable installed. A while ago I
> > successfully configured my thinkpad to use an external monitor/beamer.
> > I haven't used it for a while and after some debian unstable upgrades
> > (My guess is the step from xorg 7.0 to 7.1) this feature is broken. 
> > 
> > If I boot the thinkpad with external display attached it works fine.
> > But I cannot get the display working once X is running and I attach
> > the external display. Fn-F7 doesn't do the trick. However I noticed
> > that the monitor receives some kind of signal but does not display
> > anything. 
> > 
> > Xorg.conf snippet:  
> > 
> > Section "Device"
> > 	Identifier	"ATI Technologies, Inc. Radeon Mobility M7 LW [Radeon Mobility 7500]"
> > 	Driver		"ati"
> > 	BusID		"PCI:1:0:0"
> > 	VideoRam	32000
> > 	Option		"UseFBDev"		"false"
> > 	Option      "SWcursor" "true"
> >         Option      "DRIReinit" "true"
> >         Option      "AGPMode" "4"
> >         Option      "BIOSHotkeys" "true" 
> 
> Add
> 
> >         Option      "MergedFB" "true" 
> 
> It that still doesn't help, add
> 
>         Option          "CRT2HSync"     "30-80"
>         Option          "CRT2VRefresh"  "59-75"
> 
> To get the real hsync/vrefresh ranges, restart X so that it can detect
> the external monitor, then look them up from the EDID info in the
> Xorg.0.log.
> 
> If you're interested, my xorg.conf is here: http://mg.pov.lt/xorg.conf.
> I have the same laptop with the same Radeon 7500 video card.  I also
> often use a dual-head desktop.  I can switch between 1024x768 clone mode
> and full dual-head 1024x768+1280x1024 at runtime with
> 
>   xrandr -s 0
>   xrandr -s 1024x768
> 

Also, notice that in debian/sid there's an applet you can install for
GNOME - gnome-randr-applet, so that you don't have to open a terminal.

Cheers,
Carlos

> HTH,
> Marius Gedminas