I wrote:
	> During the /etc/daily run, with lots of "find"-ing going on, the same
	> DMA errors came back.  Back to the drawing board ... will try disabling
	> tagged queuing next.

	(Last message everyone, promise)

	Built a new kernel with the previous siop changes and tagged queuing disabled.
	While trying to make a whole new kernel (changed config file), it happened
	again:

	DMA IRQ: bus fault dma fifo empty, DSP=0x3b0 DSA=0xc006c7e0: last msg_in=0x0 status=0xff
	siop0: scsi bus reset
	cmd 0x1a3e340 (target 0:0) in reset list
	cmd 0x1a3e340 (status 2) about to be processed
	siop0: target 0 not synchronous at 20.0Mhz, offset 16
	DMA IRQ: bus fault, DSP=0x3e0 DSA=0xc006c8dc: last msg_in=0x4 status=0xff

	It then hung here for some time, finally followed by a

	sd0(siop0:0:0): command timeout

	And now it's hung completely.  I'm going back to my stable 1.5-based kernel ...

Grab the latest version of iommu.c  It fixes a dvma bug.

Eduado