Silicon Motion chip on amd64

[Free Ekanayaka]

Hi all,

I can't get xorg  working with the  Silicon Motion, Inc. SM720 Lynx3DM
(rev c1), ID 126f:0720, VGA controller on a debian/etch amd64 system.

Note that the same hardware works fine with etch/i386.

Here is the output of lscpi, the xorg.conf, and Xorg.0.log:

http://people.64studio.com/~free/xorg.conf
http://people.64studio.com/~free/lspci.output
http://people.64studio.com/~free/Xorg.0.log

I've tried both with xserver-xorg  7.0  and 7.1.  Are there any  known
issues related to this chip?

Ciao,

Free

PS: I've already asked about this issue  on the debian-x mailing list,
but got no reply so far