I've spent some time figuring how to get my Samsung flat panel to display the resolution I want, in defiance of its EDID and xorg's default actions. Don't know if it's anywhere near to what you need. Part of it was to use cvt to get a modeline:
Code:
# 1280x800 59.91 Hz (CVT 1.02MA-R) hsync: 49.31 kHz; pclk: 71.00 MHz
Modeline "1280x800R" 71.00 1280 1328 1360 1440 800 803 809 823 +hsync -vsync
The 'R' signifies using the -r|--reduced switch with cvt. From the manual:
Code:
-r|--reduced
Create a mode with reduced blanking. This allows for higher frequency signals, with a
lower or equal dotclock. Not for Cathode Ray Tube based displays though.
Valid xorg or driver options seem to change with development. I've gone through a couple, gleaned from the nvidia driver documentation, that have worked for me at one time. Currently, using 180.51, the Device section in xorg.conf looks like:
Code:
#
Section "Device"
Identifier "Device0"
VendorName "NVIDIA Corporation"
BoardName "GeForce 9500 GT"
Driver "nvidia"
Option "ExactModeTimingsDVI" "yes"
# Option "UseEDIDFreqs" "false"
# Option "ModeValidation" "DFP-1: NoMaxPClkCheck, NoEdidMaxPClkCheck, AllowNon60HzDFPModes"
The commented lines show failed tries, perhaps something that once worked but no longer does.
My experience was that my desired mode had to be first in the Display subsection and the highest resolution available; xorg seemed to go for the highest resolution.
Code:
Section "Screen"
Identifier "screen1"
Device "Device0"
Monitor "monitor1"
DefaultColorDepth 24
Subsection "Display"
Depth 8
Modes "1280x800R" "1152x720R" "1152x768" "720x480" "360x240"
EndSubsection
Subsection "Display"
Depth 15
Modes "1280x800R" "1152x720R" "1152x768" "720x480" "360x240"
EndSubsection
Subsection "Display"
Depth 16
Modes "1280x800R" "1152x720R" "1152x768" "720x480" "360x240"
EndSubsection
Subsection "Display"
Depth 24
Modes "1280x800R" "1152x720R" "1152x768" "720x480" "360x240"
EndSubsection
EndSection