panic in ide_dma_intr on KT400

[Chuck Berg]

I have a machine with a Soyo Dragon motherboard (Via KT400 chipset).

With kernels 2.5.69, 2.5.70, and 2.5.71, it panics in ide_dma_intr() while
detecting the IDE drives. If I boot with pci=noacpi or acpi=off, two of my
drives come up without DMA, rendering the system unusably slow.

With kernels 2.4.20 and 2.4.21, it panics in ide_dma_intr() during heavy
activity on the IDE drives at the same time as heavy activity on the PCI bus.
(therefore, transfering files over NFS crashes the system almost immediately).

2.4 stuff here:
http://marc.theaimsgroup.com/?l=linux-kernel&m=105167850927613&w=2

2.5 stuff: (2.5.71 doesn't behave any differently)

Bootup messages from 2.5.69 with pci=noacpi:
http://encinc.com/~chuck/kt400/2.5.69-pci=noacpi.txt

Bootup messages from 2.5.69 with acpi=off:
http://encinc.com/~chuck/kt400/2.5.69-acpi=off.txt

lspci -vvv, /proc/{cpuinfo,interrupts,iomem,ioports}:
http://encinc.com/~chuck/kt400/2.5.69-pci=noacpi-info.txt

.config:
http://encinc.com/~chuck/kt402/config-2.5.69.txt