Help with issue with mpt(4) driver

[Brian Buhrow <buhrow%nfbcal.org@localhost>]

        Hello.  I'm working on some patches to make the LSI Fusion SCSI driver
(mpt(4)) more robust.  I'm making good progress, but I've run into a n
issue that has momentarily baffled me.  If I get a bunch of concurrent jobs
running on a filesystem mounted on a raid set  using disks across two
mpt(4) instances, they get into a state where they become deadlocked and
all but one of the processes is stuck in tstile, and the other remaining
process is in uvn_fp2.  All the processes are trying to read the same file
in the filesystem, not write it, but read it.  I have a debug version of
the kernel, and the machine is running, and other operations against the
filesystem work fine and complete successfully. I'm assuming the problem is
something I've introduced into the mpt(4) driver, though I'm not sure how
at the moment, sinceI've not been able to reproduce it In an alternative
environment.
        When a process gets into uvn_fp2 state, it's waiting for something to
find it pages.  Is there  a way to figure out what it's waiting for and
which underlying kernel process the uvn_fp2 call is  expecting to wake it
up?

Any help on this issue would be greatly appreciated.  I can give a lot more
details if someone is interested.

-thanks
-Brian