From owner-freebsd-questions@FreeBSD.ORG Wed Sep 27 16:08:03 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 62F1616A412 for ; Wed, 27 Sep 2006 16:08:03 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 97D6243D79 for ; Wed, 27 Sep 2006 16:08:02 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 0ED675F56; Wed, 27 Sep 2006 12:08:02 -0400 (EDT) X-Virus-Scanned: amavisd-new at codefab.com Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7EZnTAX-c5oz; Wed, 27 Sep 2006 12:07:59 -0400 (EDT) Received: from [192.168.1.251] (pool-68-161-96-195.ny325.east.verizon.net [68.161.96.195]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 66F4D5C6D; Wed, 27 Sep 2006 12:07:59 -0400 (EDT) Message-ID: <451AA1DD.8030000@mac.com> Date: Wed, 27 Sep 2006 12:07:57 -0400 From: Chuck Swiger User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: Marty Landman References: <70063950609270820p4f104d71gae306bdf3de98ddb@mail.gmail.com> In-Reply-To: <70063950609270820p4f104d71gae306bdf3de98ddb@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: intermittent boot problem X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Sep 2006 16:08:03 -0000 Marty Landman wrote: > I've got a new FBSD 5.3 release install on an old Compaq pII-233 w/ 128M > ram. What I get when the boot fails is > > "tx underrun -- using store and forward mode" > > repeating infinitely. > > Now that a reboot has succeeded here's what dmesg shows for dc0: > > dc0: <82c169 PNIC 10/100BaseTX> port 0x1400-0x14ff mem You've got an Asante/Kingston/Linksys PNIC clone of the DEC 21x4x "Tulip" chipset. I've had four out of five of those cards die within two years. If upgrading to 5-STABLE or 6.2 BETA doesn't fix it, consider replacing the NIC with something else: The dc driver programs 82c168 and 82c169 PNIC chips to use the store and forward setting for the transmit start threshold by default. This is to work around problems with some NIC/PCI bus combinations where the PNIC can transmit corrupt frames when operating at 100Mbps, probably due to PCI DMA burst transfer errors. The 82c168 and 82c169 PNIC chips also have a receiver bug that sometimes manifests during periods of heavy receive and transmit activity, where the chip will improperly DMA received frames to the host. The chips appear to upload several kilobytes of garbage data along with the received frame data, dirtying several RX buffers instead of just the expected one. The dc driver detects this condition and will salvage the frame; however, it incurs a serious performance penalty in the process. The PNIC chips also sometimes generate a transmit underrun error when the driver attempts to download the receiver filter setup frame, which can result in the receive filter being incorrectly programmed. The dc driver will watch for this condition and requeue the setup frame until it is transfered successfully. -- -Chuck