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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, 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 88DF8C4338F for ; Mon, 2 Aug 2021 13:07:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 71DF461057 for ; Mon, 2 Aug 2021 13:07:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233799AbhHBNHj (ORCPT ); Mon, 2 Aug 2021 09:07:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233786AbhHBNHh (ORCPT ); Mon, 2 Aug 2021 09:07:37 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BF49C06175F; Mon, 2 Aug 2021 06:07:26 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id x14so24363386edr.12; Mon, 02 Aug 2021 06:07:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=+SZbqu2OmCriIcHluisGz9iJ+oJzkAqrwEFMwLWTqRc=; b=E48DER1OVUNlNN3AbK4cr/kyuJ+wfrZG9rqkLywltAeZxLroU/5TeEUkLEu96fsr1m oVGOmUS/SyZ18O20SPsgHEmuAxgyiHgAZuHEYbYwLNvSkjctNp7iqBk5VYhOxw7iDMtc OLh3jYO6kwmAd3gKoOVx1ORY5YPWE/23AtjHWFn1H+7dW6vntL2CIy2osXyKZW5f8QUF uc/gD3kx+rS0jAWqGRYV6EGlM/es/kB19OSorwE9E2JtyXs1OKV4U332y2EnsU2ryq1v I2fe512h1Sf6SVpXZ+T042Ae7py3SHuCdN9CBpj5KDWnOHjMuarnQy1O0EbtC4knR07P BVoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=+SZbqu2OmCriIcHluisGz9iJ+oJzkAqrwEFMwLWTqRc=; b=CydckpFJJDXqDES5BiRxylXGKzbcCFRnBdgv3uahgnXOZJ+iU+MaPna+5Zn3F15c0I KN2qnTte6Yd/nCC+9jm+E8C5bzmCHI/6WPyeZO9Onsiz1dtUv2sfK+8mdgjfSWU8VHZK UZ/7W1Ypym+ClxaadeWoHpMkDz7gIK1XqURZPkKrqhTNjoAp/qXOABdgpz3+ewEvjWvy e9nHiyIibFP1U9LiPXoQ82uyhNTe7g5CNJFWssMHXmqD5iHCWNPkMpHc8Plrm6ejzpN+ fxXreodf1Ho5P4wrlMO4zqp+/hKq/96vkRPlHE1TWSd2KBRip6e2LwJymqt5IVwqKS6i EzrQ== X-Gm-Message-State: AOAM533aPiOYYRnCIFQtVonMosEEcH0bmTV7KzIcNelNTGYccv/I8yqq TqmXB1ev0EForSRkpXOWuzk= X-Google-Smtp-Source: ABdhPJwDkLl+kIN1bl2f4Yw908yzO51fxWKV8HGdwOTC8AgxomlATrgugCeUjm/XBi03A5mFYLG+eA== X-Received: by 2002:aa7:d296:: with SMTP id w22mr19096988edq.170.1627909645224; Mon, 02 Aug 2021 06:07:25 -0700 (PDT) Received: from skbuf ([188.25.144.60]) by smtp.gmail.com with ESMTPSA id o3sm5969539edt.61.2021.08.02.06.07.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Aug 2021 06:07:24 -0700 (PDT) Date: Mon, 2 Aug 2021 16:07:23 +0300 From: Vladimir Oltean To: DENG Qingfang Cc: Sean Wang , Landen Chao , Andrew Lunn , Vivien Didelot , Florian Fainelli , "David S. Miller" , Jakub Kicinski , Matthias Brugger , netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Woudstra , =?utf-8?B?UmVuw6k=?= van Dorst , Frank Wunderlich Subject: Re: [RFC net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port Message-ID: <20210802130723.6tieexl5zcxu44xr@skbuf> References: <20210731191023.1329446-1-dqfext@gmail.com> <20210731191023.1329446-2-dqfext@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210731191023.1329446-2-dqfext@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Aug 01, 2021 at 03:10:19AM +0800, DENG Qingfang wrote: > Consider the following bridge configuration, where bond0 is not > offloaded: > > +-- br0 --+ > / / | \ > / / | \ > / | | bond0 > / | | / \ > swp0 swp1 swp2 swp3 swp4 > . . . > . . . > A B C > > Address learning is enabled on offloaded ports (swp0~2) and the CPU > port, so when client A sends a packet to C, the following will happen: > > 1. The switch learns that client A can be reached at swp0. > 2. The switch probably already knows that client C can be reached at the > CPU port, so it forwards the packet to the CPU. > 3. The bridge core knows client C can be reached at bond0, so it > forwards the packet back to the switch. > 4. The switch learns that client A can be reached at the CPU port. > 5. The switch forwards the packet to either swp3 or swp4, according to > the packet's tag. > > That makes client A's MAC address flap between swp0 and the CPU port. If > client B sends a packet to A, it is possible that the packet is > forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't > forward it back to the switch, resulting in packet loss. > > As we have the assisted_learning_on_cpu_port in DSA core now, enable > that and disable hardware learning on the CPU port. > > Signed-off-by: DENG Qingfang > --- Reviewed-by: Vladimir Oltean