Problems with dell 2407wfp

[André Næss]

Hi

Just got me a new 24" widescreen monitor, but I'm having some trouble
getting it to display properly.

I've got a Dell D610 laptop with the integrated 915GM graphics card.
So my first step was to use 915resolution. I patched mode 32 to be
1920x1200 24bits/pixel, and then set to work on xorg.conf. After quite
a bit of fiddling I found a modeline that "works".

Modeline        "1920x1200" 154.128 1920 1968 2000 2080 1200 1203 1209
1235 +hsync -vsync

By "works" I mean I actually get a picture. The strange thing is
however that the monitor info screen says that it's running
1600x1200 at 57Hz, while the actual desktop size is 1920x1200, meaning
320 pixels on the far right are simply lost, and the image quality is
pretty lousy too.

I've tried using the modeline generator to find a suitable modeline,
but the result requires a pixel clock of something like 200+. The
monitor only handles 170. Looking at the documentation
(http://support.dell.com/support/edocs/monitors/2407WFP/en/about.htm#Specifications)
you can see that the pixel clock keeps rising for the various
resolutions, then suddenly falls for the 1920x1200 resolution. Seems
odd to me, although I really don't understand what the pixel clock
really is.

Some relevant portions of my xorg.conf:

Section "Device"
	Identifier	"Intel Corporation Mobile 915GM/GMS/910GML Express
Graphics Controller"
	Driver		"i810"
	BusID		"PCI:0:2:0"
	Option		"UseFBDev"		"true"
        #Option		"ForceBIOS"		"800x600=1920x1200"
        Option		"NoDDC"	"1"
EndSection

Section "Monitor"
	Identifier	"Dell 2407WFP"
	Option		"DPMS"
	HorizSync	30-81
	VertRefresh	56-60
        Modeline        "1920x1200" 154.128 1920 1968 2000 2080 1200
1203 1209 1235 +hsync -vsync
EndSection