From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751303AbaDZBPb (ORCPT ); Fri, 25 Apr 2014 21:15:31 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:48439 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbaDZBP3 (ORCPT ); Fri, 25 Apr 2014 21:15:29 -0400 Message-ID: <1398474927.29914.100.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: [PATCH net-next 1/1] hyperv: Properly handle checksum offload From: Eric Dumazet To: Stephen Hemminger Cc: "K. Y. Srinivasan" , davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, stable@kernel.org Date: Fri, 25 Apr 2014 18:15:27 -0700 In-Reply-To: <20140425174322.589ed9f1@samsung-9> References: <1398451514-25593-1-git-send-email-kys@microsoft.com> <20140425174322.589ed9f1@samsung-9> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-04-25 at 17:43 -0700, Stephen Hemminger wrote: > On Fri, 25 Apr 2014 11:45:14 -0700 > "K. Y. Srinivasan" wrote: > > > @@ -474,6 +477,9 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) > > csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi + > > ppi->ppi_offset); > > > > + ip_hdr(skb)->check = 0; > > + csum_info->transmit.ip_header_checksum = 1; > > + > > if (net_trans_info & (INFO_IPV4 << 16)) > > csum_info->transmit.is_ipv4 = 1; > > else > > Linux doesn't need or want IP checksum offload. > It will not have any performance gain. BTW, was this patch even tested with IPv6 packets ???