Subject: Re: MP AS4100 hangs with 1.6?
To: Dave McGuire <>
From: Michael L. Hitch <>
List: port-alpha
Date: 11/22/2002 23:25:42
On Tue, 19 Nov 2002, Dave McGuire wrote:

>    The basic system installed fine (and *very* quickly!) but now I'm
> trying to untar a big pile of stuff (tar file on the FC-AL array,
> untarring to an empty filesystem on the system disk on the ISP1020) and
> am seeing periodic hard hangs...the only thing I've been able to do is
> hit reset.
>    Has anyone else seen this?  I'm about to boot a non-MP kernel to see
> if the behavior changes.

  This sounds very simliar to what I was seeing on my API CS20 when I was
trying to do a 1.6 kernel build.  The build would get to the kernel link,
which does lots of disk I/O and hang hard.  Since the CS20 doesn't have a
reset (as far as I know), it required a power cycle to clear.

  I was fairly certain that I had done kernel builds with MP previously,
and one of the things I had changed was a quirk for my disk drive so it
would negotiate the transfer mode properly.  After I backed that change
out, I've had no problems with it hanging during heavy disk I/O.  The
downside is that the disk probes as 8-bit async, although read speeds
appear to much faster than that would indicate.  I've not done any write
speed testing though.

  I had been thinking maybe the problem was in the esiop disk driver, but
if the problem you see is the same think as what I saw, the problem may be
elsewhere.  If there were some way you could get your driver (I'm guessing
it's the isp driver) to not negotiate wide synchronous transfers, it would
be interesting to see if it would make your system stable.  I'm not sure
how that would be done with the isp driver.

  Someday when I've got the free time (haha), I want to try tracking that
down somehow.

Michael L. Hitch