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=-12.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E6D2EC433E2 for ; Mon, 13 Jul 2020 17:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4D5B20663 for ; Mon, 13 Jul 2020 17:30:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ShX2vGdD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730412AbgGMRay (ORCPT ); Mon, 13 Jul 2020 13:30:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729644AbgGMRax (ORCPT ); Mon, 13 Jul 2020 13:30:53 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24CFDC061755 for ; Mon, 13 Jul 2020 10:30:53 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id w6so18165680ejq.6 for ; Mon, 13 Jul 2020 10:30:53 -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=2ufgH+KIQF4ucHcXcObqHa1HMkHrbW/Rw46J/1QnrK4=; b=ShX2vGdDu7Ry0EfBR8vrXAlvo9ZqOIYfPHz6DhZCVz0blafK8OIG+Mp4B/0iM3W3eP +Ot1/KQE3UNi7KU4l1zy2QzunghJ2J5pEssnKK4dFcQs8LX8WS1BbGScVz9UuJOz0doc H3iQo9fl+6lOE9tL2i7IFVdGWB+194quc79WkJjfP3M4Do6dz+Qm6Pak3Dv1HvcgfTEf xhwvgY6OXs/1c4k463VR0YXbQBvfzrDuvFVx8NiJv1QsHWDnUbd/S6JB+hLc/acxvz1E jCpHADFxyI1MoSSy9tJnG5Rjvn/75Ous45JVUXwI3LL/pKettOJWVu87DLB6+ALuzbHF pkoA== 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=2ufgH+KIQF4ucHcXcObqHa1HMkHrbW/Rw46J/1QnrK4=; b=twcda6lK0cnJHeTugO+Twp+K1eGfIrDr+k/W88AIkqaHV+HTE7PzZCFTCu4LEYH6Bv P1ugoJfHemTeO1BqwstTw1VR0CNdnSDk5jIDo8zyEkO/OTLTi1i96m2jKBqUueYhd8K8 N+P3JoGLUHqc2pEh84dALfkXLLtHJRgnppbz2EwB8jKcQq5FJEKrjdyAJIz0/ghMrZVq zQxInaVcu1p0nPrKOrZ+WTnJpi71RsJ8xIxo96MZ+VTqoxNboweByhIHvSmMvYow+CcB hEpAl0Icbx6NlFALbgBbPqXnO6oH260HuaSDnNeRCSeQXyUPjCOUw4bFWr8Babu97BS0 IlHw== X-Gm-Message-State: AOAM531eTKvSmNIzNPKES4+P4IKcNvmfPI6JucDdY1rrIMCop9wGDrWb OeWMv0DinAXcDd/Aq0dtNfM= X-Google-Smtp-Source: ABdhPJzYJ6ED6aSAWJB7+t4bKiToHxOGHwdrsVwO1RtcUILsRvPNK82sw4ZeaZG3XIh9GqrocUYinA== X-Received: by 2002:a17:906:4a17:: with SMTP id w23mr817349eju.360.1594661451847; Mon, 13 Jul 2020 10:30:51 -0700 (PDT) Received: from skbuf ([188.25.219.134]) by smtp.gmail.com with ESMTPSA id x19sm11631083eds.43.2020.07.13.10.30.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 10:30:51 -0700 (PDT) Date: Mon, 13 Jul 2020 20:30:49 +0300 From: Vladimir Oltean To: Andrew Lunn Cc: davem@davemloft.net, netdev@vger.kernel.org, f.fainelli@gmail.com, vivien.didelot@gmail.com, xiyou.wangcong@gmail.com, ap420073@gmail.com Subject: Re: [PATCH net] net: dsa: link interfaces with the DSA master to get rid of lockdep warnings Message-ID: <20200713173049.wzo7e2rpbtfbwdxd@skbuf> References: <20200713162443.2510682-1-olteanv@gmail.com> <20200713164728.GH1078057@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200713164728.GH1078057@lunn.ch> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Andrew, On Mon, Jul 13, 2020 at 06:47:28PM +0200, Andrew Lunn wrote: > > diff --git a/net/dsa/slave.c b/net/dsa/slave.c > > index 743caabeaaa6..a951b2a7d79a 100644 > > --- a/net/dsa/slave.c > > +++ b/net/dsa/slave.c > > @@ -1994,6 +1994,13 @@ int dsa_slave_create(struct dsa_port *port) > > ret, slave_dev->name); > > goto out_phy; > > } > > + rtnl_lock(); > > + ret = netdev_upper_dev_link(master, slave_dev, NULL); > > + rtnl_unlock(); > > + if (ret) { > > + unregister_netdevice(slave_dev); > > + goto out_phy; > > + } > > Hi Vladimir > > A common pattern we see in bugs is that the driver sets up something > critical after calling register_netdev(), not realising that that call > can go off and really start using the interface before it returns. So > in general, i like to have register_netdev() last, nothing after it. > > Please could you move this before register_netdev(). > > Thanks > Andrew It doesn't work after register_netdev(). The call to netdev_upper_dev_link() fails and no network interface gets probed. VLAN performs registration and linkage in the same order: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/net/8021q/vlan.c#n175 So I think this part is fine. Thanks, -Vladimir