Subject: Anyone willing to help debug a NetBSD PAS SCSI driver
To: NetBSD Users List <>
From: Chris Tham <christie@sedho.australia.NCR.COM>
List: netbsd-users
Date: 12/06/1993 11:01:36

I spent the weekend cobbling up a NetBSD low level SCSI device driver that
talks to the NCR5380 SCSI chip in the Pro Audio Spectrum 16.  By the way,
I'm doing this on NetBSD-0.9, not NetBSD-current.

I used the mac68k/dev/scsi.c driver as a starting point, converted it from
a memory map interface to a port interface, and then inserted bits from
the Linux device driver pas16.c and NCR5380.c.

Current status: mostly works, except I'm having weird timing problems, esp.
when I'm selecting a target (I'm testing this on a NEC CDR-84JD-1, maybe
this is a bad device?).  I had to greatly increase the timeout for waiting
for a device select (from 250 ms to 2.5 s!!!) and insert arbitrary DELAY()s
into the code.  I got it almost working on Sunday afternoon: It was probing
and attaching the NEC drive correctly, and I can mount a CD-ROM, ls -l etc.
Then I broke it and now its not attaching the device anymore although I'm
sure if I play with the delay timings I can get it working again.
(yes, I know, famous last words!)

My problem(s) are:
1. I don't really know how the NetBSD SCSI driver interface works.
2. I don't understand the SCSI protocol.
3. I don't know much about the NCR5380.
4. I'm basically a novice when it comes to writing device drivers.

So, apart from the above, I think I should have no problems in getting the
thing to work -- NOT!!! ;-).

If anyone who is interested wants to have a look, feel free
to mail me and I'll send you a copy of my driver.