Still debugging why open("/dev/lpt0"...) hangs

[george+freebsd at m5p.com]

lpt0 is hanging up when it tries to request the ppbus (line 478 of
lpt.c).  I'm guessing that if_plip.c has requested it and not
released it, which apparently happens when there's been an ioctl
on the plip.  There's no plausible reason why this should happen.
What can I call in lpioctl (if_plip.c line 302) to print out some
identifying information about the process doing the ioctl?  Or is
there a better list somewhere to ask this question?
-- George Mitchell