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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D284C433FE for ; Tue, 7 Dec 2021 18:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240719AbhLGSxR (ORCPT ); Tue, 7 Dec 2021 13:53:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231469AbhLGSxQ (ORCPT ); Tue, 7 Dec 2021 13:53:16 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E175C061574; Tue, 7 Dec 2021 10:49:46 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id f18-20020a17090aa79200b001ad9cb23022so167558pjq.4; Tue, 07 Dec 2021 10:49:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=F/yQUYPsKD97ChDwdkNkfz44U9dpuQ4WBjbleQG98/E=; b=LbVbUXWsfZvhqVEzvwIL8AWfCXH2pgPaxusH5esX0jmp/82r2m+yzmdaIk1+Hdfc+h T41Q3xVWc6syDwemIOY/DrCInlH+IH7fXpeKjC78UM6qrXb/uXTGs2GzuAvoWJfDhPSc bcYh/CjCp3FND+D5m9tweZGsb51oYkaVRkPdsSd/1WXjX+LREJvpHkP0rOkNbiAuhQk1 z+ekQNw8pNDYUAANOHQNabow/Wk7FTjvdHSJiUm6rI5r2lTMDTFX7dsDKaQ2K9LqHsX9 Z5dCqSyXoSFhQdZfq6CnzLjXV5RalxhJzdhQAh0AOYPV/XH9UEv8MWY5Sy1quaH2m0ra 8CxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=F/yQUYPsKD97ChDwdkNkfz44U9dpuQ4WBjbleQG98/E=; b=2Wx2xYEX3tA8KJxuZISxJssL7UTGJu9xv9Gs+Czvr93j562wnuNztCcPr70PbwAK5F 71QOLUYw6IvT975jRgMxQtBDM4KP+86nMv+4ETWlNeOlZKQpdYuqo8osaCnyC1nuBFa4 RPWXL01c8WdCdUBCMAp1DyJ24jzvj7VWdM3xpLvZRQTR33Kvo5EyjnSL2RmJy52x4EEL CM1p1Zpd5vO21iyvGAQ9lXPSKcfZ/X+2UrhI84Ghuo7Y5iBHpVKilNFCVe3Pg0vElYkN C2Wsk7giP5S5rSxWEy+PGR5IhtRf84IJiA7PrLiTwX4qPcf6M/Duny+0bP9mIsu8GcoG UVHQ== X-Gm-Message-State: AOAM531nUg3TJ2kAUdD3dfeLAs6lbyylNcD/MELnvXV2n7Rz7Au19J8i T92ys9vKTz/LRcvkaZtL4I8fk9S1HSo= X-Google-Smtp-Source: ABdhPJztD0YkRSk81b4tQ6fGccnYyGJuM/brVDyBXBGHtfsn0/bm1lFXxsNpHyPtDzIPqs7ECB2tNw== X-Received: by 2002:a17:90b:1e4e:: with SMTP id pi14mr978686pjb.161.1638902985031; Tue, 07 Dec 2021 10:49:45 -0800 (PST) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id 38sm220370pgl.73.2021.12.07.10.49.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 07 Dec 2021 10:49:44 -0800 (PST) Subject: Re: [net-next RFC PATCH 0/6] Add support for qca8k mdio rw in Ethernet packet To: Andrew Lunn , Ansuel Smith Cc: Vivien Didelot , Vladimir Oltean , "David S. Miller" , Jakub Kicinski , linux-kernel@vger.kernel.org, netdev@vger.kernel.org References: <20211207145942.7444-1-ansuelsmth@gmail.com> From: Florian Fainelli Message-ID: <77203cb2-ba90-ff01-5940-2e9b599f648f@gmail.com> Date: Tue, 7 Dec 2021 10:49:43 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/7/21 7:15 AM, Andrew Lunn wrote: > On Tue, Dec 07, 2021 at 03:59:36PM +0100, Ansuel Smith wrote: >> Hi, this is still WIP and currently has some problem but I would love if >> someone can give this a superficial review and answer to some problem >> with this. >> >> The main reason for this is that we notice some routing problem in the >> switch and it seems assisted learning is needed. Considering mdio is >> quite slow due to the indirect write using this Ethernet alternative way >> seems to be quicker. >> >> The qca8k switch supports a special way to pass mdio read/write request >> using specially crafted Ethernet packet. > > Oh! Cool! Marvell has this as well, and i suspect a few others. It is > something i've wanted to work on for a long long time, but never had > the opportunity. > > This also means that, even if you are focusing on qca8k, please try to > think what could be generic, and what should specific to the > qca8k. The idea of sending an Ethernet frame and sometime later > receiving a reply should be generic and usable for other DSA > drivers. The contents of those frames needs to be driver specific. > How we hook this into MDIO might also be generic, maybe. > > I will look at your questions later, but soon. There was a priori attempt from Vivien to add support for mv88e6xxx over RMU frames: https://www.mail-archive.com/netdev@vger.kernel.org/msg298317.html This gets interesting because the switch's control path moves from MDIO to Ethernet and there is not really an "ethernet bus" though we could certainly come up with one. We have mdio-i2c, so maybe we should have mdio-ethernet? -- Florian