Unknown card - presumably because this is an AIW X1900 XT instead of a regular X1900.  (http://ati.amd.com/products/radeonx1900/aiwx1900/specs.html)

I'm just using the DVI port not the AIW functionality.

Pulled radeonhd from git 2007-11-24.

Xorg.0.log excerpts:
(--) PCI:*(7:0:0) ATI Technologies Inc R580 [Radeon X1900 XT] Primary rev 0, Mem @ 0xc0000000/28, 0xdffe0000/16, I/O @ 0xe800/8, BIOS @ 0xdffc0000/17
(--) PCI: (7:0:1) ATI Technologies Inc R580 [Radeon X1900 XT] Secondary rev 0, Mem @ 0xdfff0000/16

(WW) RADEONHD(0): Unknown card detected: 0x7249:0x1002:0x0412.
(--) RADEONHD(0): Detected an R580 on an unidentified card


lspci -v 

07:00.0 VGA compatible controller: ATI Technologies Inc R580 [Radeon X1900 XT] (Primary) (prog-if 00 [VGA])
        Subsystem: ATI Technologies Inc Unknown device 0412
        Flags: bus master, fast devsel, latency 0, IRQ 18
        Memory at c0000000 (64-bit, prefetchable) [size=256M]
        Memory at dffe0000 (64-bit, non-prefetchable) [size=64K]
        I/O ports at e800 [size=256]
        Expansion ROM at dffc0000 [disabled] [size=128K]
        Capabilities: [50] Power Management version 2
        Capabilities: [58] Express Endpoint IRQ 0
        Capabilities: [80] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-

07:00.1 Display controller: ATI Technologies Inc R580 [Radeon X1900 XT] (Secondary)
        Subsystem: ATI Technologies Inc Unknown device 0413
        Flags: bus master, fast devsel, latency 0
        Memory at dfff0000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [50] Power Management version 2
        Capabilities: [58] Express Endpoint IRQ 0


lspci -v -n

07:00.0 0300: 1002:7249 (prog-if 00 [VGA])
        Subsystem: 1002:0412
        Flags: bus master, fast devsel, latency 0, IRQ 18
        Memory at c0000000 (64-bit, prefetchable) [size=256M]
        Memory at dffe0000 (64-bit, non-prefetchable) [size=64K]
        I/O ports at e800 [size=256]
        Expansion ROM at dffc0000 [disabled] [size=128K]
        Capabilities: [50] Power Management version 2
        Capabilities: [58] Express Endpoint IRQ 0
        Capabilities: [80] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-

07:00.1 0380: 1002:7269
        Subsystem: 1002:0413
        Flags: bus master, fast devsel, latency 0
        Memory at dfff0000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [50] Power Management version 2
        Capabilities: [58] Express Endpoint IRQ 0