Using "Supported additional Video Mode" with i810 driver?

[Pete Toscano]

Hello,

I'm trying to get a cow-orker's Dell 2005FPW working on a Dell OptiPlex 
gx280.  It uses the intel 915 chipset, thus the i810 x.org driver.  The 
monitor does native 1680x1050 and when booted into Windows, it works 
fine.  When booted into Fedora Core 3 (using the 6.8.1-12.FC3.21 
package, I get a blank screen with "invalid mode."

After doing some Google'ing, I found someone suggesting a modeline to 
try.  I added the modeline to the monitor section, then tried that.  It 
fell back to 800x600 (the backup mode I was using).  Looking through the 
Xorg.0.log file, I found that it was ignoring the modeline resolution. 
I tried some variations and all failed.  Someone suggested to me that I 
try disabling DDC, saying that the i810 driver would ignore modelines if 
DDC was enabled, but that didn't seem to help either.

Someone in the xorg IRC channel on freenode.net said that the i810 
driver ignores all modelines, regardless.  I'm on the verge of declaring 
that this monitor + X.org just won't display in 1680x1050, at least at 
this time.

One interesting thing I did find, though, was this in the Xorg.0.log file:

I810(0): Supported additional Video Mode:
I810(0): clock: 146.2 MHz   Image Size:   434 x 270 mm
I810(0): h_active: 1680  h_sync: 1784  h_sync_end 1960 h_blank_end 2240 
h_border: 0
I810(0): v_active: 1050  v_sync: 1050  v_sync_end 1059 v_blanking: 1089 
v_border: 0

So, it looks to me that the i810 driver "sees" this resolution and I 
used this info to make a modeline (but it was ignored).  How on earth do 
I tell X.org to use this resolution?

Thanks,
pete