Subject: Increase your hangtime with NetBSD 1.1
To: None <>
From: Bruce Albrecht <>
List: amiga
Date: 12/03/1995 09:46:47
   From: (Ralph Seichter)

   Well, I got a problem with NetBSD 1.1. In three out of five boot attempts,
   NetBSD will check the SCSI bus for devices and then just hang. The bus LED
   glows steadily without a flicker, there's no hard disk access, and after a
   while I get messages like the following:

     sbicwait TIMEO@2006 with asr=x80 csr=x4f
     sbicwait TIMEO@2013 with asr=x0 csr=x4f

   I heard rumours about the -I flag of loadbsd, but to be honest I have not
   the slightest idea what "sync-inhibit" stands for and how to use it. Any
   takers? If there's a FAQ to answer my question, please point me to it.

I don't know what the sbicwait messages indicate, but I'm pretty sure
that this is related to the sync-inhibit.  By default, NetBSD-1.1 (for
the Amiga only) puts all SCSI devices into synchronous mode because
it's somewhat faster than async mode.  For some reason, some SCSI
devices don't like this, and lock up the SCSI bus, cause the bus LED
to glow steadily without a flicker.  The new loadbsd has a -I flag
which tells the kernel's SCSI drivers not to try to set sync mode on
specific devices.  

I don't know how many SCSI devices you have, but you can do one of two
things.  First, try -Iff, which will attempt to boot with sync mode
disabled for all devices.  I think this is equivalent to what you
would have seen with NetBSD-1.0. 

Second, you can turn off sync mode for the device(s) that locks up
with -I1 (for SCSI unit 0, -I2= unit 1, -I4= unit 2, -I8= unit 3,
-I10= unit 4, -I20= unit5, -I40= unit 6, -I80= unit 7).  If you do
this, you may have to do it more than once, in which case you would
turn off each device which causes lockups (for example, -I15 would
turn of sync for units 0, 2, and 4).  I would do this rather than turn
off sync-mode for all devices.