Xen Kernel (3.0.2) breaks b44 module

[<xen@wood.id.au>]

I have a new laptop (Dell 9400) that I am trying to work with Xen 3.0.

Xen works fine, runs windows XP under HVM.

But, the Xen kernel on Dom0 has a few problems with some of the hardware.

The network card is a Broadcom 4400 10/100BaseT.

Normally loading the b44 module gives this:

Apr 28 20:07:53 ipanema kernel: [4294683.185000] b44.c:v0.97 (Nov 30, 2005)
Apr 28 20:07:53 ipanema kernel: [4294683.185000] ACPI: PCI Interrupt
0000:03:00.0[A] -> GSI 17 (level, low) -> IRQ 177
Apr 28 20:07:53 ipanema kernel: [4294683.189000] eth0: Broadcom 4400
10/100BaseT Ethernet 00:14:22:f2:57:36

(under an Ubuntu kernel - 2.6.15-21-686 #1 SMP PREEMPT)
Works similarly under a vanilla 2.6.16.

When running a Xen patched 2.6.16 (as per
https://wiki.ubuntu.com/XenVirtualMachine/XenOnUbuntuDapper) or on the Xen
live CD, I get:

Apr 27 00:28:31 ipanema kernel: [   20.038669] b44.c:v0.97 (Nov 30, 2005)
Apr 27 00:28:31 ipanema kernel: [   20.038700] ACPI: PCI Interrupt
0000:03:00.0[A] -> GSI 17 (level, low) -> IRQ 17
Apr 27 00:28:31 ipanema kernel: [   20.038710] b44: No usable DMA
configuration, aborting.
Apr 27 00:28:31 ipanema kernel: [   20.040248] ACPI: PCI interrupt for
device 0000:03:00.0 disabled
Apr 27 00:28:31 ipanema kernel: [   20.040251] b44: probe of 0000:03:00.0
failed with error -5

Am I doing something wrong?

The first difference here is that ACPI allocates IRQ 17 instead of IRQ
177.  Hope that rings bells for somebody :-)

This is the relevant output of lspci -vvvv while it's running under 2.6.16:
0000:03:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0
100Base-TX (rev 02)
        Subsystem: Dell: Unknown device 01cd
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
ParErr- Stepping- SERR+ FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort-
<MAbort- >SERR- <PERR-
        Latency: 64
        Interrupt: pin A routed to IRQ 177
        Region 0: Memory at dcbfe000 (32-bit, non-prefetchable) [size=8K]
Capabilities: [40] Power Management version 2
                Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA
PME(D0+,D1+,D2+,D3hot+,D3cold+)
                Status: D0 PME-Enable- DSel=0 DScale=2 PME-

and the first two lines of lspci -nvvvv

0000:03:00.0 0200: 14e4:170c (rev 02)
        Subsystem: 1028:01cd

Laptop is Dell 9400 Core Duo T2600 2Gb Ram , SATA 100Gb

The ultimate aim is to use the Intel VT extensions to run unmodified OSes
underneath, but that's not that useful without networking.

Other hints of problems: noticable graphics corruption under framebuffer
console while running xen kernel. Also the cdrom is inaccessible under the
Xen Kernel.

cheers,
Woody

PS: I posted this to Xen-user previously but got no answers :-(