From owner-freebsd-net@FreeBSD.ORG  Thu Jun 12 15:17:21 2008
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3FE1C106566C
	for <freebsd-net@freebsd.org>; Thu, 12 Jun 2008 15:17:21 +0000 (UTC)
	(envelope-from yonyossef.lists@gmail.com)
Received: from yx-out-2324.google.com (yx-out-2324.google.com [74.125.44.29])
	by mx1.freebsd.org (Postfix) with ESMTP id 022418FC1B
	for <freebsd-net@freebsd.org>; Thu, 12 Jun 2008 15:17:20 +0000 (UTC)
	(envelope-from yonyossef.lists@gmail.com)
Received: by yx-out-2324.google.com with SMTP id 31so383234yxl.13
	for <freebsd-net@freebsd.org>; Thu, 12 Jun 2008 08:17:20 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:received:received:message-id:date:from:to
	:subject:cc:mime-version:content-type;
	bh=EqhrSHoRvznXaILaP7FKlQBpIMR/lI4OMCfptZQOYIE=;
	b=fupx5qpq6x94fbfkPVX6HQkKxD38eB6jIwrHpCujOypQeXQShhm1E/f+3hD4rTRoDn
	3GdoaR1EhG+DXMg1HOf4H2Ra2W6qWAox6FlsSgxO4Bt0OlMU/5A87zFPsdm6tx4MUlx5
	67Me2scXHf8JdLxykyzK0AvuaGO7bbaYpgoKQ=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=message-id:date:from:to:subject:cc:mime-version:content-type;
	b=d0kOdxUbHTPyec6KkR7HggRBIR1p4F0lAx2RjNLQ6pgI6TgFbq+i1RXcDhGWlflLIo
	6/kREzRHvtJNlS8oD8EEpcMmp6amDIubR+uTYCa+CdkTjJbCtMC65U+ma77kwCFXeNnm
	1KOAKHpsUgZ+EwMkds0/v5m5AMdzWyPE6xwvM=
Received: by 10.151.45.6 with SMTP id x6mr2547489ybj.6.1213283840347;
	Thu, 12 Jun 2008 08:17:20 -0700 (PDT)
Received: by 10.151.84.2 with HTTP; Thu, 12 Jun 2008 08:17:20 -0700 (PDT)
Message-ID: <20def4870806120817q5b755805hfafa0d0d1523f2ad@mail.gmail.com>
Date: Thu, 12 Jun 2008 18:17:20 +0300
From: "Yony Yossef" <yonyossef.lists@gmail.com>
To: freebsd-net@freebsd.org
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Cc: liranl@mellanox.co.il
Subject: TSO bug in FreeBSD 7.0 ?
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 12 Jun 2008 15:17:21 -0000

Hi freebsd-net,

I'm seeing mbuf chains larger than 64K being sent down by FreeBSD 7 when TSO
is enabled.
Then my driver crashes in bus_dmamap_load_mbuf_sg (error=EINVAL).
I'm printing the mbuf m_pkthdr.len size right after the DEQUEUE from the
stack:

IFQ_DRV_DEQUEUE(&dev->if_snd, m_head);
if (m_head == NULL)
   break;
        if (m_head->m_pkthdr.len > 65000) {
            printf("TSO packet mbuf len:%d\n", m_head->m_pkthdr.len);
        }
and the output is:

....
TSO packet mbuf len:65387
TSO packet mbuf len:65417
TSO packet mbuf len:65447
TSO packet mbuf len:65477
TSO packet mbuf len:65507
TSO packet mbuf len:65537
mtnic0: bus_dmamap_load_mbuf_sg error: 22
xmit_failure:12
...

Note the 65537, I've also seen TSO packets sized 65542.

There's this old thread talking about it:
http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2007-02/msg00312.html
but I've seen no solution for this bug.

Is there a fix for that?

Thanks,

Yony