Subject: RE: 1.3_ALPHA silo overflows
To: None <chrismc@aldiscon.ie>
From: Michael L. Hitch <mhitch@msu.oscs.montana.edu>
List: port-amiga
Date: 11/23/1997 11:02:49
Chris McCarthy <chrismc@aldiscon.ie> writes: 
> Another problem I have is with silo overflows coming from the
> serial port. I have a supra33.6 connecting at 28.8k. It worked
> fine before, but now I get silo overflows. I read the FAQ and
> it said to recompile the kernel with options "LEV6_DEFER" and
> "SERIBUF_SIZE=8192". Are these options that were removed from
> the amiga kernel in 1.3 ? If so, why ?

  I'm not sure, but I don't think the GENERIC kernel uses those options,
and I don't remember the GENERIC kernel ever having them defined.

  What you may be seeing though, is a fix to the serial driver that
will now detect and report the receive buffer overflows that were being
missed before.  While debugging the ncr53c9x driver [SCSI driver for the
Phase 5 SCSI interfaces], I found that I (and another person helping test
the SCSI driver) got numerous errors and poor performance over a PPP
link using the internal serial port.  I couldn't figure out why I was
getting so many errrors without reports of the serial buffer overflow.  I
found that the serial driver was clearing the RBF interrupt before reading
the serial data, which I think was clearing the buffer overrun status bit.
After changing the driver to read the serial data before clearing the RBF
interrupts, I found that the driver was now reporting the serial overruns
that matched the PPP errors I was getting.

Michael
---
Michael L. Hitch                        mhitch@montana.edu
Computer Consultant,  Information Technology Center
Montana State University, Bozeman, MT     USA