Subject: Re: ahc bug in current? (was: ccd changed in current?)
To: Chris G. Demetriou <email@example.com>
From: None <firstname.lastname@example.org>
Date: 08/29/1997 16:49:26
> > While this may or may not be the problem, you should know that the DECchip
> > 21050 is a first-generation PCI-to-PCI bridge and contains a serious design
> > flaw. It is susceptible to deadlock under certain conditions. Under certain
> > cirumstances where a downstream and an upstream transaction are trying to
> > proceed through a 21050 simultaneously, neither transaction will ever proceed.
> Actually, I was under the impression (from discussions i'd seen about
> the bug over a year ago) that the problem was specific to the Intel
> Triton chipset, and was in fact a Triton bug which had been worked
> around in later revs of the PPB...
> However, my understanding could well be out of date, since it was
Well, I'm not qualified to say what deadlock problems the Triton chipset may
or may not have (it probably has some bugs), but I can say for certain that
we experienced crippling deadlock problems when using 21050s with the
AXPpci33 (Digital Alpha 21066 motherboard, which certainly doesn't use the
Triton chipset :) ). Does anyone know what PPB Adaptec is now using on the
3940UW? One would hope that's it's no longer the 21050...