Neil Woolford wrote:
Just about to calibrate my new twin head X11 Ubuntu Linux 64 bit AMD system, running two DVI interfaced flat screens with the Xinerama extension. Runnning dispwin shows the colour squares on both displays (choose with -d option), but the screen doesn't darken or lighten at the end of the sequence. I take this to mean that the LUT isn't being updated by the program.
You can use diswin -r to test just this aspect.
Before I look into this further, are there any known issues with the Matrox P650 card and Argyll? As far as I know, the card is supposed to have two LUTs, one for each output channel. One of several reasons that I selected it...
I don't have any personal experience with modern Matrox cards (most of my Video cards are NVIDIA), but it comes down to how the XF86VidMode extensions are implemented on the X11 server. You don't say whether you are using accelerated binary drivers (does Matrox offer them ?) , or the Xorg server. If dispwin doesn't return an error, it's kind of strange that nothing happens on either screen when the LUT's are being accessed. If you run without Xinerama of any other multi-screen extension, what $DISPLAY value lets you access each screen ? If you use the -display option instead of -d, in this configuration, are the LUT's accessible ? Otherwise all I can suggest is perhaps asking on an ATI/X11 oriented mailing list about XF86VidMode extensions for your particular setup. Graeme Gill.