From owner-freebsd-hackers Sat Dec 15 1:14:27 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from root.com (unknown [209.102.106.178]) by hub.freebsd.org (Postfix) with ESMTP id E522B37B417 for ; Sat, 15 Dec 2001 01:14:24 -0800 (PST) Received: (from dg@localhost) by root.com (8.11.2/8.11.2) id fBF94vp84911; Sat, 15 Dec 2001 01:04:57 -0800 (PST) (envelope-from dg) Date: Sat, 15 Dec 2001 01:04:57 -0800 From: David Greenman To: rsharpe@ns.aus.com Cc: freebsd-hackers@freebsd.org Subject: Re: Does anyone know if the Broadcom BCM5700 has problems with HW csum? Message-ID: <20011215010457.B84861@nexus.root.com> References: <3C1AEA9E.6010502@ns.aus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3C1AEA9E.6010502@ns.aus.com>; from sharpe@ns.aus.com on Sat, Dec 15, 2001 at 04:45:58PM +1030 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG >I am playing with a driver for the Broadcom 5700/5701. > >It recognizes the 5700 in my 3Com cards OK, but seems to screw up the >TCP checksum. > >Switching off hardware checksum capability fixes it. > >Does anyone know the details of which stepping this stuff worked on? I haven't nailed down the problem that I've seen with them to a specific chipset, but I can confirm that they incorrectly calculate the checksum on input packets in some cases. It seems to be related to both packet size and certain TCP options (or lack of them). I've only seen the problem occur with very small (0-4 byte payload) packets. In any case, after discussing this problem with Bill Paul, I disabled input checksum in the -current driver and intend to merge that to -stable in a few days. -DG David Greenman Co-founder, The FreeBSD Project - http://www.freebsd.org President, TeraSolutions, Inc. - http://www.terasolutions.com Pave the road of life with opportunities. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message