Matrox G400 and DDC Problem

Hello, List,

There was a thread running for a couple of weeks during October and
November about the Matroc G550 cards not doing DDC properly, or at
least not returning really useful results. I've had the same problem
with my G400. I've noodled around with it off and on and haven't gotten
any joy. Nonetheless, I did discover that the Matrox cards do appear
to have OS-level I2C drivers, at least for Linux.  From the help file 
from the kernel configuration tools:

    "This drivers [sic] creates I2C buses which are needed for 
    accessing the DDC (I2C) bus present on all Matroxes, an I2C 
    bus which interconnects Matrox optional devices, like MGA-TVO 
    on G200 and G400, and the secondary head DDC bus, present on 
    G400 only.  

    You can say Y or M here if you want to experiment with monitor 
    detection code. You must say Y or M here if you want to use either 
    second head of G400 or MGA-TVO on G200 or G400.

    If you compile it as module, it will create a module named 
    i2c-matroxfb.o."

This is from the 2.4 kernel sources (2.4.20-pre3, to be precise). I
compiled this module and inserted it, but it didn't appear to make any
difference, that is, the DDC probe with "X -configure" and at runtime
did not produce any additional information that I could see. The G450 
and G550 aren't mentioned, but my guess is that they are too new to have 
been documented in the help file. I've been running the CVS version of
XFree86 (4.2.99.2), if that makes any difference.

I haven't tried this with the 2.5 kernel series because, frankly, I need
to get work done. ;-) 

I'll be happy to help Andrew or anyone else try to track this down once
the feature freeze and 4.3 release has passed and there are spare cycles
to spend on it.

Thanks and regards,

Kurt
-- 
Don't steal; thou'lt never thus compete successfully in business.
Cheat.
		-- Ambrose Bierce