Fire GL 9000 with Cinema Display

[Beat Fluri]

> I've had lots of reports of this display not working properly with the
> modeline obtained from the EDID block, with either X or radeonfb.
> 
> A user managed to get the 23" working with that modeline:
> 
> # 1920x1200 @ 60Hz
> Modeline "1920x1200" 193.156 1920 2048 2256 2592 1200 1201 1203 1242 
> +hsync +vsync
> 
> I don't know about the 20".

I have found some Modelines for 20". How can I force that X use a 
spezific Modeline. The log tells me that X always uses the Modeline from 
EDID. I use "DDCMode" "off" but that does not have any impact. I also 
use UseModes "..." in the Monitor section with a corresponding Modes 
section, but X does not seem to consult these Modes...

--Beat