From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BB08C18E5B for ; Tue, 24 Mar 2020 23:19:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D411820663 for ; Tue, 24 Mar 2020 23:19:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727101AbgCXXTe (ORCPT ); Tue, 24 Mar 2020 19:19:34 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:37786 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbgCXXTd (ORCPT ); Tue, 24 Mar 2020 19:19:33 -0400 Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 442EC159F477C; Tue, 24 Mar 2020 16:19:33 -0700 (PDT) Date: Tue, 24 Mar 2020 16:19:32 -0700 (PDT) Message-Id: <20200324.161932.2119088651104512505.davem@davemloft.net> To: olteanv@gmail.com Cc: netdev@vger.kernel.org, andrew@lunn.ch, f.fainelli@gmail.com, vivien.didelot@gmail.com Subject: Re: [PATCH net] net: dsa: tag_8021q: replace dsa_8021q_remove_header with __skb_vlan_pop From: David Miller In-Reply-To: <20200324094534.29769-1-olteanv@gmail.com> References: <20200324094534.29769-1-olteanv@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 24 Mar 2020 16:19:33 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vladimir Oltean Date: Tue, 24 Mar 2020 11:45:34 +0200 > From: Vladimir Oltean > > Not only did this wheel did not need reinventing, but there is also > an issue with it: It doesn't remove the VLAN header in a way that > preserves the L2 payload checksum when that is being provided by the DSA > master hw. It should recalculate checksum both for the push, before > removing the header, and for the pull afterwards. But the current > implementation is quite dizzying, with pulls followed immediately > afterwards by pushes, the memmove is done before the push, etc. This > makes a DSA master with RX checksumming offload to print stack traces > with the infamous 'hw csum failure' message. > > So remove the dsa_8021q_remove_header function and replace it with > something that actually works with inet checksumming. > > Fixes: d461933638ae ("net: dsa: tag_8021q: Create helper function for removing VLAN header") > Signed-off-by: Vladimir Oltean Applied and queued up for -stable.