On Wed, 12 Jul 1995, der Mouse wrote:

> [This was sent to current-users; I'm sending to port-sparc because my
> comments are purely sparc-related.]
> 
> > 2) When I try to shutdown, halt, or reboot the machine, it panics on
> >    "DMAWAIT1" when it tries to sync the disks.  This happens every
> >    time, even if I boot and immediately halt.  [...]
> 
> I got this sometimes, and someone told me to do something to some call
> in dma.c; I've forgotten what.  But on reading the source, I decided
> to, instead, goose the "count" initialization in the TIME_WAIT macro in
> sys/arch/sparc/dev/dmavar.h.  It's set to 500000, I think, as
> distributed; I just tacked on another zero.  Any true hang will still
> be caught, but it's a good deal more tolerant of slow-to-complete DMA.
> Never seen a DMAWAIT1 panic since.

Well, I tried this. Now it sits for ten times as long when syncing, but 
it still panics. The disk it is trying to sync is SCSI2--could this be 
the problem? Note that it has no trouble handling the sync() syscall, or 
the sync(8) program. Where might I find the reboot-syscall-related code 
in the kernel source? I've looked with to no avail...

Thanks for any further advice.

--Aaron