[ltp] xorg.conf for t42p + Dell 2407wfp monitor - SOLVED

Yury linux-thinkpad@linux-thinkpad.org
Tue, 26 Dec 2006 15:05:06 -0800


On Tuesday 26 December 2006 09:03, Alex Deucher wrote:
> On 12/26/06, Marius Gedminas <mgedmin@b4net.lt> wrote:
> > On Mon, Dec 25, 2006 at 03:37:02PM -0800, Yury wrote:
> > > On Monday 25 December 2006 05:48, Marius Gedminas wrote:
> > > > The log file should also mention why it considers 1920x1200
> > > > unsupported, a few tens of lines above this bit.
> > >
> > > I have posted my xorg.conf and the log to
> > >
> > > http://www.blin.com/web/xorg.conf
> > > http://www.blin.com/web/Xorg.1.0.log
> > >
> > > I think the monitor reports 1920x1200 as "Supported additional Video
> > > Mode" however it doesn't get listed under CRTC2 modes found for
> > > MergeFB.
> >
> > Yes.  It looks like the X server doesn't know anything about a 1920x1200
> > mode (it discards a couple of 1920x1440 modes for various reasons, but
> > doesn't even mention 1920x1200, other than saying it's not supported).
> >
> > If I'm right, then all you need to do is specify a ModeLine.  This:
> >
> > (II) RADEON(0): Supported additional Video Mode:
> > (II) RADEON(0): clock: 154.0 MHz   Image Size:  519 x 324 mm
> > (II) RADEON(0): h_active: 1920  h_sync: 1968  h_sync_end 2000 h_blank_end
> > 2080 h_border: 0 (II) RADEON(0): v_active: 1200  v_sync: 1203  v_sync_end
> > 1209 v_blanking: 1235 v_border: 0
> >
> > translates into
> >
> >   ModeLine "1920x1200"  154  1920 1968 2000 2080  1200 1203 1209 1235
> >
> > and the X server could easily do it automatically.  I've no idea why it
> > doesn't.  *sigh*  Perhaps the new randr will fix that?
> >
> > The only problem is that I've no idea where to put the Modeline.
> > According to man xorg.conf, Modelines are supposed to be placed in the
> > Monitor section.  But when you use MergedFB, you don't actually have a
> > Monitor section for the external display.  Will it work if you place the
> > mode in the Monitor section for the internal display?  I guess the only
> > way to find out is to try it.
>
> Put it in the monitor section.  Any modes specified there will end up
> in a global mode pool that is used for both heads when using mergedfb.
>
> Alex

I did put the Modeline into the Monitor section. 
After that the problem has changed to:
(II) RADEON(0): Not using mode "1920x1200" (width too large for virtual size)

After googling that one for a while, found a tip to decrease the upper limit 
for the horizontal frequency (from 80kHz to 74kHz as needed for 1920 mode).
After changing "CRT2HSync" option to "31-74" the setup is now functional!

Thanks to everybody who provided suggestions!

The next step would be to get the same setup with the DVI connection ;-)

Yury