SMART2P in Proliant 5500 fails with 3.3 cac(4), works with 3.2 cac(4)

[Dan Brosemer <odin@svartalfheim.net>]

I'm trying to fix a problem in the 3.3 cac(4) driver I found during an
upgrade of my Proliant 5500.  It has this controller:
cac0 at pci2 dev 0 function 0 "Compaq SMART2P RAID" rev 0x02: irq 11 Compaq SMART-2/P

After upgrading to OpenBSD 3.3, the machine would lock, seemingly, after a
certain ammount of time.  It didn't seem IO related.  (an idle machine would
lock about as quickly as one running fsck or newfs).

There was no panic message.  The console simply becomes unresponsive, and
the activity lights on the RAID1 set are on solid.  (Tried this with only
one RAID1 set).

Once I undid the changes that went into sys/dev/ic/cac.c,
sys/dev/ic/cac{var,reg}.h, and sys/dev/pci/cac_pci.c, all is well.

Obviously, I'd like to not have to do this for the next release, so I'm
trying to find out exactly what the problem is so I can fix it, and would
appreciate any pointers and debugging hints others can offer.

Thanks in advance.

-Dan

-- 
"Burnished gallows set with red
 Caress the fevered, empty mind
 Of man who hangs bloodied and blind
 To reach for wisdom, not for bread."  -- Deoridhe Grimsdaughter