From owner-freebsd-hackers Fri Aug 22 11:47:35 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id LAA25389 for hackers-outgoing; Fri, 22 Aug 1997 11:47:35 -0700 (PDT) Received: from sendero-ppp.i-connect.net (sendero-ppp.i-Connect.Net [206.190.143.100]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id LAA25382 for ; Fri, 22 Aug 1997 11:47:29 -0700 (PDT) Received: (qmail 4567 invoked by uid 1000); 22 Aug 1997 18:47:46 -0000 Message-ID: X-Mailer: XFMail 1.2-alpha [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=iso-8859-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <199708221807.LAA26407@phaeton.artisoft.com> Date: Fri, 22 Aug 1997 11:47:46 -0700 (PDT) Organization: Atlas Telecom From: Simon Shapiro To: Terry Lambert Subject: Re: Final request for help with release. (DPT boot floppy) Cc: tom@sdf.com, hackers@FreeBSD.ORG, mrcpu@cdsnet.net, nate@mt.sri.com, (Satoshi Asami) Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Hi Terry Lambert; On 22-Aug-97 you wrote: > > I have also seen mysterious lockups (for a few seconds) with Solaris > > x86 when I bombarded more than two twin-channel controllers (Adaptec > > 3940W/UW) with lots of requests. FreeBSD had no problems whatsoever. > > This is probably a PCI issue. Most Intel PCI bridges do not > correctly arbitrate between more than two bus mastering PCI > devices simultaneously. > > Stefan posted about this a while back. > > I think there's a newer chipset that actually supports any number > of devices (up to the number of slots, anyway), but I don't remember > the name of the thing off the top of my head. You are right. We had here a terrible time with PCI bridges. Some will deliver interrupts before completion of DMA, some will lose interrupts, some will corrupt DMA transfers. Real party. Not only Intel but (for sure) the older DEC bridge (somethign with 50 in the name, vs. 51). Simon