From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: tg3 issue with tcp checksums and vlan packets Date: Tue, 16 Sep 2014 12:43:21 -0400 Message-ID: <541868A9.7080407@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" To: Prashant Sreedharan , Michael Chan Return-path: Received: from mail-qa0-f50.google.com ([209.85.216.50]:42214 "EHLO mail-qa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751213AbaIPQnY (ORCPT ); Tue, 16 Sep 2014 12:43:24 -0400 Received: by mail-qa0-f50.google.com with SMTP id dc16so144743qab.37 for ; Tue, 16 Sep 2014 09:43:23 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Prashant and Michael I am seeing a strange issue with tg3 driver when I try to pass to it tcp packets that have partial checksums and inline (non-accelerated) vlan header. Looking at the packet at the receiver, it appears as if the tcp checksum is never updated. If I strip the vlan header and set vlan_tci, then everything works ok. You can easily reproduce this by configuring 802.1ad vlans on top of tg3 device. This will force software tagging, tg3 will not fix checksums and tcp connections will not be established. I've looked at tg3 driver and it doesn't look like it tries to pass any checksum offsets to the nic/firmware. So it looks like a possible firmware issue. Can you please take a look. Thanks -vlad