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 phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 54A82C77B7E for ; Thu, 1 Jun 2023 16:47:01 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 05F3F86345; Thu, 1 Jun 2023 18:46:59 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="MxHYLNpl"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 99A7286357; Thu, 1 Jun 2023 18:46:57 +0200 (CEST) Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [IPv6:2a00:1450:4864:20::52b]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 3D20484768 for ; Thu, 1 Jun 2023 18:46:55 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=olteanv@gmail.com Received: by mail-ed1-x52b.google.com with SMTP id 4fb4d7f45d1cf-5162d2373cdso1458686a12.3 for ; Thu, 01 Jun 2023 09:46:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685638014; x=1688230014; 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=8k4+U3oCKRl3K4rQzNIQXDQPKUtLwtkJWeNX2JO2TKQ=; b=MxHYLNplN2DbZWThSxdj/ewtBwpDTcEif9amXQEvXB10RB7kEFlFOqKbPcJ8HtmZQc iyTu3iVcoJ2oTD5T7XJWypjh0dAvDtMkT8hc8cKP/s1tZeXD52z1bNZL/lMquRTJ/AIF WOCrG0KrSOCwReMRAmS8+x2E1IIFmPw7wbadQdFJb92thzOadRYOlhBXnz+IYv18fK+v Jh1VNSK6MeOuVON+TV/XZBDpSf4zRxzCs27BIQimbvyoh2BkHZ4RcEUkXbq8DFn5QueN s1bmiHWbf77bW7TR3LuZDTSMOxCd9t4zzh0F6joKW4BugSFp0UqFHMb9C1QmQp6twhMU VBUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685638014; x=1688230014; 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=8k4+U3oCKRl3K4rQzNIQXDQPKUtLwtkJWeNX2JO2TKQ=; b=kjnSx8tI00KmGjLbPqxRoNCBF/P6HYlNYXCz9AHZCjZOH6X3DOhAVgRjEqz7g9Oi8f UgbCG59PhiiAvoYZh4DAbuIaBFOUVd1KhnT3UqmfnPzap1iFv/GcAZj/Pzjr6u3OlFso TFvzWwXilGs7aLAFK0ZpZXINAxJr3544pyUiFZPZXXKg7sXqavsKhM8SbymyK0i+caxW aOm2+YLcvZr55eTYVQlNdvOSwAkfFMKRgg+Xx3+VNvt9iR9+naZNcb0c4Tgt66uQQd9a GfgVF0J/hwM5W7GHvqbILLWFPLiyOdXuUI/6XKuf7nzurCKMlm5czJWSvxks9lxavX4n l5cQ== X-Gm-Message-State: AC+VfDzyY52wjIfoUhRt1CO+gVwgNZQo/npEU1W3CqrwPjMMnC6qB4Qe EF4z3auX0YgjdrdOWDhlUuc= X-Google-Smtp-Source: ACHHUZ7jNekeqYyU6EJX+13r71z/KcJXvTJkVpIA9pf/RKPRTNbnWjhb2za4GQlz2uwtnf6bexYZLA== X-Received: by 2002:a17:907:94c7:b0:96f:aed9:2535 with SMTP id dn7-20020a17090794c700b0096faed92535mr8716626ejc.9.1685638014383; Thu, 01 Jun 2023 09:46:54 -0700 (PDT) Received: from skbuf ([188.27.184.189]) by smtp.gmail.com with ESMTPSA id q15-20020a1709066b0f00b0096b4c3489e6sm10959431ejr.177.2023.06.01.09.46.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jun 2023 09:46:54 -0700 (PDT) Date: Thu, 1 Jun 2023 19:46:51 +0300 From: Vladimir Oltean To: Lukasz Majewski Cc: Marek Vasut , u-boot@lists.denx.de, Tom Rini , Anatolij Gustschin , Ramon Fried , Joe Hershberger , Marek Vasut , Michal Simek , Tim Harvey Subject: Re: [PATCH v1 2/6] net: mv88e61xx: Configure PHY ports to also pass packets between them Message-ID: <20230601164651.tquily3zoi2hhgwt@skbuf> References: <20230601100005.2216345-1-lukma@denx.de> <20230601100005.2216345-3-lukma@denx.de> <0ab25898-2fe6-7d86-7d63-ff3d43e82b63@mailbox.org> <20230601130251.12f18dca@wsk> <83893eea-7a3e-8fc1-da43-aa50149fa11c@mailbox.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83893eea-7a3e-8fc1-da43-aa50149fa11c@mailbox.org> X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean Hi Lukasz, On Thu, Jun 01, 2023 at 01:44:30PM +0200, Marek Vasut wrote: > I think after two years, it would be good to drop the RB tags and do another > round of reviews. To expand on Marek's point. In those past 2 years, Tim Harvey has put in a considerable amount of effort to add another driver for mv88e6xxx that uses DM_DSA. I believe the current "PHY" driver for the same hardware should be considered obsolete until all platforms are converted to DM_DSA, then it can be deleted. So, no new features for it. Then, there's also the question of the sanity of the proposed change itself. I believe that we need to be humble enough to recognize that the U-Boot network stack is not competent enough to handle the switching capabilities of a switch, not even enough for it to be safe. It doesn't handle STP (Spanning Tree Protocol), for one thing. So it will never be capable of detecting switching loops, such as to block one of its ports in order to not kill the network. In principle, I would say: as long as there is no plan to handle STP, there should be no plan to allow autonomous packet forwarding from U-Boot. The U-Boot network stack is there so that you can TFTP a kernel and boot it, which is also the only use case behind DM_DSA. But you may say: I'm never going to allow packet forwarding from U-Boot in a network with loops! Okay, but your patch suggests otherwise. Which ports allow forwarding is a compile-time option, which... is by definition contrary to any runtime network topology determinations. Maybe enabling forwarding between switch ports through a CLI command that communicates with DM_DSA would be tolerable - assuming that users are smart enough to not use it in a network with STP. But again, I'm not really sure what's the use case.