This should apply to 2.5.59 too.  It seems to get rid of some pesky
hangs, on at least some hardware, but I won't have time to test it
on either VIA version ... maybe someone else will make the time?  :)

      New QH state prevents a re-activation race
	- nobody can un-halt a qh before its cleanup is done
	- resubmit-from-completion had this race (some usbtest cases)
	  as could some normal submit paths on busy endpoints (storage)
	- faster controllers would trip on this more consistently

      Queues of qtds
	- work harder to avoid ever modifing any qh in software
	- short reads block queue advance much less often
	- be more cautious with large (>~19KB) unaligned buffers

      Unlinking urbs
	- if qtd unlinked is at queue head, use its latest status
	  (main effect is reporting bytes from partial transfers)
	- another new qh state:  defer qh unlink if IAA is busy
	  (eliminates a busy-wait loop in a rare scenario)

      Enable features to improve bus utilization
	- PCI MWI ... can produce better write throughput; and by
	  using right cacheline size, sometimes read throughput too
	- USB NAK throttle ... sometimes reduces PCI access rates

      Other
	- async dump shows more funky qh+qtd states, and NAK count
	- cope with with some of the sprintf wierdness
	- periodic dump is usually smaller (so is that schedule)
      	- minor cleanups