[Intel-gfx] Problems configuring unique xorg.conf file

[Alan W. Irwin]

On 2010-08-26 10:47-0000 Nasa wrote:

> Hi,
>
>
> I am trying to configure a rather obscure resolution (800x480) which is the
> native resolution for my monitor.  The monitor doesn't provide EDID or DDC
> information (it's connected over VGA).  And the default settings by the
> driver produces displays that don't fit the monitor properly.  I would like
> to construct a xorg.conf file with appropraite vertical refresh rates, horizontal
> syncs, and/or modelines to work correctly with the monitor.  However, there
> doesn't seem a way to turn off the driver defaults for those items. I tried options
> like NoDDC, UseEDID, etc with no luck.  I also tried using xrandr to change
> resolutions after X has started.  The results end up being worse than the
> intial problem I was trying to fix (ie: the screen is bigger than the area
> available to display it).  I expect my inability to find a suitable solution
> is due to my lack of knowledge -- so I hope someone can fill me in to what
> I am missing.  Thanks in advance,

Earlier this year before I replaced my long-time Sony monitor with an
LCD, and upgraded from Debian Lenny to Debian testing, the results of
gtf and PreferredMode worked for me. For example, my xorg.conf file
for that monitor had the following lines in the Monitor section

#gtf 1024 768 85
# 1024x768 @ 85.00 Hz (GTF) hsync: 68.60 kHz; pclk: 94.39 MHz
Modeline "1024x768_85.00"  94.39  1024 1088 1200 1376  768 769 772 807
-HSync +Vsync
Option "PreferredMode" "1024x768_85.00"

Of course, intead of using the above example, you will want to run
something like

gtf 800 400 85

from the command line (man gtf), paste the results to your Monitor
section, and consistently update the identification of the mode used
by PreferredMode.

I emphasize the above configuration lines worked for an old version of the
Intel driver (Debian Lenny), and I don't know whether they  would work
for a modern version.  But it is worth a try.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of
Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
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