Oversized ethernet problems

Donald Becker becker@cesdis.gsfc.nasa.gov
Tue Oct 19 18:44:21 1999


On Tue, 19 Oct 1999, P.A.M. van Dam (Pascal) wrote:

> On Mon, Oct 18, 1999 at 04:29:06PM -0400, Donald Becker wrote:
> > What type of machine do you have?
> 
> AMD K6/II 300Mhz not overclocked.
> EPOX MVP3 Mobo PCI/AGP
> 
> > The frame overflows are likely a result of PCI bus errors during transfers,
> > e.g. most '486 machines have a problem with PCI bursts.
> > 
> > You can try changing the RX_DMA_BURST setting to something smaller, perhaps
> > to '1' or '2'.
> 
> Neither 2 nor 1 does solve the problem.

OK, it's likely not a burst-size bug.
I still suspect an unreported PCI bus error of some sort.  It appears to be
shifting the Rx status word from its expected location.

One suggestion from the list is updating to the latest 2.3.* kernel, which
reports some PCI problem with some chipsets.

It may be that I'll have to add in code to emit the data words before and
after the expected status location to see if they contain a valid status
word.

Donald Becker
Scyld Computing Corporation, and
USRA-CESDIS,   becker@cesdis.gsfc.nasa.gov

 | To unsubscribe, send mail to Majordomo@cesdis.gsfc.nasa.gov, and within the
 |  body of the mail, include only the text:
 |   unsubscribe this-list-name youraddress@wherever.org
 | You will be unsubscribed as speedily as possible.