spurious interrupts: 4/470+4.1.1+xy7053+xy472

[Ed Arnold]

The subject system is a 4/470 whose CPU has been upgraded to rev -12, and
whose OS has been upgraded to 4.1.1, in response to Sun's claim that the
problems with intermixing IPI, SMD, and/or xy472 controllers would be
solved by making those changes.

This system does not have a Sun-supplied 7053, however.  It has Xylogics
7053-106-211s (with 2.23 PROM) in slots 10 and 11.  (Xylogics tells us
2.23 is the latest rev; I don't know if it is equivalent to Sun's
501-1249-04 level SMD.)  The Xylogics 472 is in slot 9.

When a tape is written and read back, we see spurious interrupt messages:

	spurious VME interrupt at processor level 9
	VME level 5, VME vector 0xffffffff

usually accompanied by a message from the xt driver:

	xt0: stray interrupt

Has anyone out there (esp. those who are using 3rd-party 7053s) been able
to run a xy472 in your 4/400 without the spurious interrupts?  If so, what
is the solution?

Please respond directly to me if you have any info; will summarize.
Thanks in advance ...

era at ncar.ucar.edu