From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751745Ab0DKKJO (ORCPT ); Sun, 11 Apr 2010 06:09:14 -0400 Received: from ringil.hengli.com.au ([216.59.3.182]:47081 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751130Ab0DKKJN (ORCPT ); Sun, 11 Apr 2010 06:09:13 -0400 Date: Sun, 11 Apr 2010 18:09:02 +0800 From: Herbert Xu To: David Miller Cc: yinghai@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, torvalds@linux-foundation.org Subject: Re: ssh server etc doesn't work anymore with net-2.6 Message-ID: <20100411100902.GA20141@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100411.024352.209996508.davem@davemloft.net> Organization: Core X-Newsgroups: apana.lists.os.linux.kernel,apana.lists.os.linux.netdev User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Miller wrote: > From: Yinghai Lu > Date: Sun, 11 Apr 2010 02:32:33 -0700 > >> server side: 82576 with net-2.6 >> client side: opensuse 11.2 on thinkpad T61 wireless + vpnc > > I've pushed out a revert, we'll sort this out in net-next-2.6 > and meanwhile I've started a dialog with the Intel driver > folks to see if there IGB chip has a problem with handling > CHECKSUM_PARTIAL packets with a zero length data area. > > Thanks for your report. I was confused at first as to whether it was CHECKSUM_UNNECESSARY that broke or CHECKSUM_PARTIAL. After looking at the actual net-2.6 tree I see that it is actually CHECKSUM_PARTIAL that caused this breakage. The fact that when this was first implemented we didn't use hw checksums on dataless packets might not have been an oversight after all. As I don't think such packets have been tested all by our kernel on any NICs, and given the fact that IGB apparently broke, I think the risk of this change is too high. However, all is not lost as we can still adopt the approach of the actual patch subject :) That is, we can use CHECKSUM_UNNECESSARY for packets checksummed locally by software. This does need a lot more testing so it should spend some time in net-next first. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt