From owner-freebsd-atm Tue Jan 16 9:55:53 2001 Delivered-To: freebsd-atm@freebsd.org Received: from smtp1.sentex.ca (smtp1.sentex.ca [199.212.134.4]) by hub.freebsd.org (Postfix) with ESMTP id 0017A37B402 for ; Tue, 16 Jan 2001 09:55:35 -0800 (PST) Received: from simoeon.sentex.net (simeon.sentex.ca [209.112.4.47]) by smtp1.sentex.ca (8.11.1/8.11.1) with ESMTP id f0GHtXM41260; Tue, 16 Jan 2001 12:55:33 -0500 (EST) (envelope-from mike@sentex.net) Message-Id: <5.0.1.4.0.20010116121839.033a2a70@marble.sentex.ca> X-Sender: mdtpop@marble.sentex.ca X-Mailer: QUALCOMM Windows Eudora Version 5.0.1 Date: Tue, 16 Jan 2001 12:49:17 -0500 To: Richard Hodges From: Mike Tancsa Subject: Re: ATM under 4.x STABLE (DMA and en driver ?) Cc: freebsd-atm@FreeBSD.ORG In-Reply-To: References: <5.0.1.4.0.20010116114713.033bd7c0@marble.sentex.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-atm@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org At 09:18 AM 1/16/01 -0800, Richard Hodges wrote: >On Tue, 16 Jan 2001, Mike Tancsa wrote: > > > > en0: mem 0xfe000000-0xfe3fffff irq 11 at > > device 8.0 on pci1 > > en0: unexpected timeout in rx DMA test > > en0: WARNING: DMA test detects a broken PCI chipset! > > trying to work around the problem... but if this doesn't > > work for you, you'd better switch to a newer motherboard. > >Ouch! Looking at /usr/src/sys/dev/en/midway.c I see some very interesting >notes about broken DMA in the Efficient card (but not Adaptec). The >driver is supposed to work around that, though. Your DMA message above >seems to refer to the chipset not being able to handle "misaligned 64 >byte DMA", which might not be a major problem, but just might reduce >the performance. > >Of course, the real authority is Chuck Cranor himself... Hmmm... Any guesses as to how much of a performance drop ? If its a hardware issue, I wonder if the LINUX crowd has run into this. Time to do some more archive searching! BTW, for my simple protocol requirements, should I try and pick up a couple of used Fore cards instead ? I am hoping the box will be able to forward 30-50Mb/s over its life time. ---Mike To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-atm" in the body of the message