From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [Patch net v2] mlx5: fixup checksum for short ethernet frame padding Date: Mon, 03 Dec 2018 15:17:24 -0800 (PST) Message-ID: <20181203.151724.648093455366632499.davem@davemloft.net> References: <20181128061013.3885-1-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, saeedm@mellanox.com, edumazet@google.com To: xiyou.wangcong@gmail.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:49438 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725880AbeLCXRZ (ORCPT ); Mon, 3 Dec 2018 18:17:25 -0500 In-Reply-To: <20181128061013.3885-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Cong Wang Date: Tue, 27 Nov 2018 22:10:13 -0800 > When an ethernet frame is padded to meet the minimum ethernet frame > size, the padding octets are not covered by the hardware checksum. > Fortunately the padding octets are ususally zero's, which don't affect > checksum. However, we have a switch which pads non-zero octets, this > causes kernel hardware checksum fault repeatedly. > > Prior to commit 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends"), > skb checksum is forced to be CHECKSUM_NONE when padding is detected. > After it, we need to keep skb->csum updated, like what we do for FCS. > > The logic is a bit complicated when dealing with both FCS and padding, > so I wrap it up in a helper function mlx5e_csum_padding(). > > I tested this patch with RXFCS on and off, it works fine without any > warning in both cases. > > Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends"), > Cc: Saeed Mahameed > Cc: Eric Dumazet > Signed-off-by: Cong Wang Saeed, are you going to take care of this?