From owner-freebsd-mobile Mon Jan 27 17:51:24 2003 Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B00CA37B401 for ; Mon, 27 Jan 2003 17:51:22 -0800 (PST) Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4244A43F85 for ; Mon, 27 Jan 2003 17:51:21 -0800 (PST) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id D865951980; Tue, 28 Jan 2003 12:21:18 +1030 (CST) Date: Tue, 28 Jan 2003 12:21:18 +1030 From: Greg 'groggy' Lehey To: Joerg Wunsch Cc: mobile@freebsd.org, Kevin Oberman Subject: Re: How to make an Intel EtherExpress known to xe(4)? Message-ID: <20030128015118.GQ56320@wantadilla.lemis.com> References: <20030125235520.A97813@uriah.heep.sax.de> <20030125230756.BC4195D06@ptavv.es.net> <20030127000131.B27981@uriah.heep.sax.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030127000131.B27981@uriah.heep.sax.de> User-Agent: Mutt/1.4i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 Sender: owner-freebsd-mobile@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Monday, 27 January 2003 at 0:01:31 +0100, Joerg Wunsch wrote: > As Kevin Oberman wrote: > >> This is typical of receiving 802.1q tagged frames, but I have been >> getting this error on my current system with a Xircom RE-100 card >> and I am reasonably sure that i am not getting any tagged frames >> where it's located. > > Me too. The remote end is running a vx0 which i think couldn't > even emit 802.1q tags at all. > > It's a bug in the driver, or an oddity of the xe hardware, depending > on the point of view. Unlike many other devices, it seems these chips > do indeed deliver the FCS along with the packet, and set the length > appropriately. > > Browsing through the source reveals that our network code could > already handle this situation, only the driver needs to set the > M_HASFCS flag. The attached patch would do this. If nobody objects, > i'll commit that. > > The only remaining oddity is then that tcpdump displays the incoming > packet (and length) including the FCS. > > I verified that the xe(4) driver in 4.x (where the card worked > flawlessly so far) also experienced this behaviour, i. e. the upper > network layers obviously silently ignored the trailing FCS. Only now > in 5.x, the kernel complains about oversized packets and discards > them. OK, I've tried this one, and it now works on my machine. What would be the implication of using this code with a card which doesn't return the FCS? Greg -- See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message