From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5D5683D86 for ; Mon, 11 Sep 2023 17:02:30 +0000 (UTC) Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [IPv6:2a00:1450:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3F7A123; Mon, 11 Sep 2023 10:02:28 -0700 (PDT) Received: by mail-ed1-x536.google.com with SMTP id 4fb4d7f45d1cf-52713d2c606so6135845a12.2; Mon, 11 Sep 2023 10:02:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1694451747; x=1695056547; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Bx7Z3G6TG2avGQh5qW28D9cnQGBkHNI8APKRcgvj8pQ=; b=nzuNuEfgJoaZ8ctfulG9O+a/kGh8zC6E9VJUaiPDATak0p9ytn7SKAFK8xH8pkpGUD Ca+U21EH4GczWFII6EUbOH3DluQoVgEBjeyqMpV3Lxh3A29C6O6F7rrvsJKjrOx42s/g gvCPYS5tkrAVqofszHR1y+UwLWz+q+54ofzcc9BA7VzgUa2sx9EpcilPQ/TuvhLa3NUD l4SKENpu2UUw8uftvPk2ZQY/lnKhdkAe83MB1WxHYElekbOIyWvb5mN9y+72BI8wUnKs vExRWHvfYzjFvszEOUJQHvOtQaCiPg5cV1o1Er+pBnmpsAyxBosgZ/H8PQkHce+N12Xl Zq7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694451747; x=1695056547; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Bx7Z3G6TG2avGQh5qW28D9cnQGBkHNI8APKRcgvj8pQ=; b=WIQfsHcVkN3VTZECugZFar3+5VceFekPx1yWowjZ+OzP2gINwzB6xYt01bBHFFTC3z SC5TwNOdgmsT10kgkhHC3jpwX2SYHdLyd68kgbJsDD1fHsJ6qvXGgHt3GBwRhTdwwLew Pt/uqaMBhi0+zTh+XkVkdNYz9bJtlxuxgovRQEF4krIZh1MFT9LcLIMqsC8Aavd2irHH TFmzGa7tjH3xkAMi7mQica/6fIoN/GGjyX5JqeYbmy0pTPktrkiKfgqoYZ92MSGbDezf 5np7jcGESja+izxuL1guvkv3tx7E6zCb/EMliPykrvAIp9VBd2Y4ZmDn3eXruwZ30rkT GlJA== X-Gm-Message-State: AOJu0YyenXBsUkfD8cvrPKN2JCaXxMLNGn8iD2c5fKdrfD823Y2dCsax r6shksHHISnfgKITbul9pbY= X-Google-Smtp-Source: AGHT+IFdN1FH5jz8hi8cj7z87DfB50l9K9XRcmjaFnVCZO7Htji79T4QMjFEDfv19+SOFie1FB70MA== X-Received: by 2002:a17:906:8475:b0:9a1:b5fc:8c56 with SMTP id hx21-20020a170906847500b009a1b5fc8c56mr8914915ejc.55.1694451746889; Mon, 11 Sep 2023 10:02:26 -0700 (PDT) Received: from skbuf ([188.26.56.202]) by smtp.gmail.com with ESMTPSA id se22-20020a170906ce5600b009920e9a3a73sm5674085ejb.115.2023.09.11.10.02.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Sep 2023 10:02:24 -0700 (PDT) Date: Mon, 11 Sep 2023 20:02:22 +0300 From: Vladimir Oltean To: Lukasz Majewski Cc: Tristram.Ha@microchip.com, Eric Dumazet , Andrew Lunn , davem@davemloft.net, Woojung Huh , Oleksij Rempel , Florian Fainelli , Jakub Kicinski , Paolo Abeni , UNGLinuxDriver@microchip.com, Oleksij Rempel , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [[RFC PATCH v4 net-next] 0/2] net: dsa: hsr: Enable HSR HW offloading for KSZ9477 Message-ID: <20230911170222.hip2pcyzbfu3olau@skbuf> References: <20230906152801.921664-1-lukma@denx.de> <20230911165848.0741c03c@wsk> <20230911160501.5vc4nttz6fnww56h@skbuf> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230911160501.5vc4nttz6fnww56h@skbuf> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Mon, Sep 11, 2023 at 07:05:01PM +0300, Vladimir Oltean wrote: > Actually, the reason why I haven't yet said anything is because it made > me realize that there is a pre-existing bug in net/dsa/slave.c where we > have this pattern: > > if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) > dev_uc_add(master, dev->dev_addr); > > but there is no replay of the dev_uc_add() call when the master->dev_addr > changes. This really results in RX packet loss, as I have tested. I don't > know what is the best way to solve it. Hi @Jakub, I remember you fixed some issues with the dev->dev_addr writes, after dev_addr_lists.c was changed to a rbtree. Is it easy for you to tell if the change below is safe from an API perspective? Is the answer "yes, because dev_uc_add() uses an addr_type of NETDEV_HW_ADDR_T_UNICAST, and dev->dev_addr uses NETDEV_HW_ADDR_T_LAN, so they never share a struct netdev_hw_addr for the same MAC address, and thus, they never collide"? The DSA and 8021q drivers currently have this pattern, from around 2008. But 8021q also tracks NETDEV_CHANGEADDR events on the real_dev, which is absent in DSA. If the change below is safe, it would be a simpler solution. diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 48db91b33390..e40474e13660 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -374,11 +374,9 @@ static int dsa_slave_open(struct net_device *dev) goto out; } - if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) { - err = dev_uc_add(master, dev->dev_addr); - if (err < 0) - goto del_host_addr; - } + err = dev_uc_add(master, dev->dev_addr); + if (err < 0) + goto del_host_addr; err = dsa_port_enable_rt(dp, dev->phydev); if (err) @@ -387,8 +385,7 @@ static int dsa_slave_open(struct net_device *dev) return 0; del_unicast: - if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) - dev_uc_del(master, dev->dev_addr); + dev_uc_del(master, dev->dev_addr); del_host_addr: if (dsa_switch_supports_uc_filtering(ds)) dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0); @@ -404,8 +401,7 @@ static int dsa_slave_close(struct net_device *dev) dsa_port_disable_rt(dp); - if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) - dev_uc_del(master, dev->dev_addr); + dev_uc_del(master, dev->dev_addr); if (dsa_switch_supports_uc_filtering(ds)) dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0); @@ -469,14 +465,11 @@ static int dsa_slave_set_mac_address(struct net_device *dev, void *a) return err; } - if (!ether_addr_equal(addr->sa_data, master->dev_addr)) { - err = dev_uc_add(master, addr->sa_data); - if (err < 0) - goto del_unicast; - } + err = dev_uc_add(master, addr->sa_data); + if (err < 0) + goto del_unicast; - if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) - dev_uc_del(master, dev->dev_addr); + dev_uc_del(master, dev->dev_addr); if (dsa_switch_supports_uc_filtering(ds)) dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);