Xorg and multi-domain PCI bus

[Giulio Sichel <cypher@tiscali.it>]

Hi,
I'm running Etch on a Sun Ultra 30 (sparc 64). Recently I've pulled out
a 3dfx Voodoo Banshee from a PC and inserted it in the Ultra:

Mater:~# lspci
0000:80:00.0 Host bridge: Sun Microsystems Computer Corp. Psycho PCI Bus 
Module
0001:00:00.0 Host bridge: Sun Microsystems Computer Corp. Psycho PCI Bus 
Module
0001:00:01.0 Bridge: Sun Microsystems Computer Corp. EBUS (rev 01)
0001:00:01.1 Ethernet controller: Sun Microsystems Computer Corp. Happy 
Meal (rev 01)
0001:00:02.0 Bridge: Sun Microsystems Computer Corp. EBUS (rev 01)
0001:00:02.1 Ethernet controller: Sun Microsystems Computer Corp. Happy 
Meal (rev 01)
0001:00:03.0 SCSI storage controller: LSI Logic / Symbios Logic 53c875 
(rev 03)
0001:00:05.0 VGA compatible controller: 3Dfx Interactive, Inc. Voodoo 
Banshee (rev 03)

The Banshee is detected by the kernel (2.6.14.3) but Xorg seems to scan 
just only
one PCI domain (0000:80) and so it can't see the Banshee:

Mater:~# Xorg :1 -scanpci
Probing for PCI devices (Bus:Device:Function)

(128:0:0) Sun Microsystems Computer Corp. Psycho PCI Bus Module

I've googled and I've discovered that other people using multi-domain 
PCI computers encountered the same problem, but I've not found any real
solution.
Any suggestions?

Thank you