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 33109C433DF for ; Tue, 26 May 2020 00:58:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11D57206F1 for ; Tue, 26 May 2020 00:58:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388251AbgEZA6K (ORCPT ); Mon, 25 May 2020 20:58:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387794AbgEZA6K (ORCPT ); Mon, 25 May 2020 20:58:10 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 125FDC061A0E for ; Mon, 25 May 2020 17:58:10 -0700 (PDT) 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 79D071279E51A; Mon, 25 May 2020 17:58:09 -0700 (PDT) Date: Mon, 25 May 2020 17:58:08 -0700 (PDT) Message-Id: <20200525.175808.465482238114904305.davem@davemloft.net> To: olteanv@gmail.com Cc: andrew@lunn.ch, f.fainelli@gmail.com, vivien.didelot@gmail.com, madalin.bucur@oss.nxp.com, netdev@vger.kernel.org Subject: Re: [PATCH] dpaa_eth: fix usage as DSA master, try 3 From: David Miller In-Reply-To: <20200524212251.3311546-1-olteanv@gmail.com> References: <20200524212251.3311546-1-olteanv@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.3 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]); Mon, 25 May 2020 17:58:09 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vladimir Oltean Date: Mon, 25 May 2020 00:22:51 +0300 > From: Vladimir Oltean > > The dpaa-eth driver probes on compatible string for the MAC node, and > the fman/mac.c driver allocates a dpaa-ethernet platform device that > triggers the probing of the dpaa-eth net device driver. > > All of this is fine, but the problem is that the struct device of the > dpaa_eth net_device is 2 parents away from the MAC which can be > referenced via of_node. So of_find_net_device_by_node can't find it, and > DSA switches won't be able to probe on top of FMan ports. > > It would be a bit silly to modify a core function > (of_find_net_device_by_node) to look for dev->parent->parent->of_node > just for one driver. We're just 1 step away from implementing full > recursion. > > Actually there have already been at least 2 previous attempts to make > this work: > - Commit a1a50c8e4c24 ("fsl/man: Inherit parent device and of_node") > - One or more of the patches in "[v3,0/6] adapt DPAA drivers for DSA": > https://patchwork.ozlabs.org/project/netdev/cover/1508178970-28945-1-git-send-email-madalin.bucur@nxp.com/ > (I couldn't really figure out which one was supposed to solve the > problem and how). > > Point being, it looks like this is still pretty much a problem today. > On T1040, the /sys/class/net/eth0 symlink currently points to > > ../../devices/platform/ffe000000.soc/ffe400000.fman/ffe4e6000.ethernet/dpaa-ethernet.0/net/eth0 > > which pretty much illustrates the problem. The closest of_node we've got > is the "fsl,fman-memac" at /soc@ffe000000/fman@400000/ethernet@e6000, > which is what we'd like to be able to reference from DSA as host port. > > For of_find_net_device_by_node to find the eth0 port, we would need the > parent of the eth0 net_device to not be the "dpaa-ethernet" platform > device, but to point 1 level higher, aka the "fsl,fman-memac" node > directly. The new sysfs path would look like this: > > ../../devices/platform/ffe000000.soc/ffe400000.fman/ffe4e6000.ethernet/net/eth0 > > And this is exactly what SET_NETDEV_DEV does. It sets the parent of the > net_device. The new parent has an of_node associated with it, and > of_dev_node_match already checks for the of_node of the device or of its > parent. > > Fixes: a1a50c8e4c24 ("fsl/man: Inherit parent device and of_node") > Fixes: c6e26ea8c893 ("dpaa_eth: change device used") > Signed-off-by: Vladimir Oltean Applied and queued up for -stable, thanks.