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=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 6BDA3C43331 for ; Tue, 12 Nov 2019 13:53:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F6EB2196E for ; Tue, 12 Nov 2019 13:53:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dNU2oGuX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727363AbfKLNxE (ORCPT ); Tue, 12 Nov 2019 08:53:04 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:35854 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725847AbfKLNxD (ORCPT ); Tue, 12 Nov 2019 08:53:03 -0500 Received: by mail-ed1-f65.google.com with SMTP id f7so14974942edq.3 for ; Tue, 12 Nov 2019 05:53:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=F6hTFtvbCS9Rrf/QydOMqYK3BwvfL9UyV16fF7L9MzU=; b=dNU2oGuXtu/k7U4ZX9iHlRojJrVqZEO5n9ni38BgZ9A/qVnOxvM0/C8GL58mlfazuP S4F4zjbtdqWXffhYykBkpJ20Xfu9NilgpGvqwC5RVmwwjSptuol9K0EDprbQLR5Gc87B Z9RKQBTEh/d3Bf/L/t4uPxCuYbUsvaVnzJIzaBXCpevhWj5afSME6AQ+71hXredXBrIy bTQ9znmzJS8SnVi/yBG+o7Pleks3jgvx1A/SZ3kNar+5ZPeS9JNf73qrb8hM1FM73uvE FkVpsuMi5xTZmiQAF20T2y6Y484vd0uL8+uWZYQVYS+GnALUMEv0y+1D9u6Q/VM5BjdB jHQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=F6hTFtvbCS9Rrf/QydOMqYK3BwvfL9UyV16fF7L9MzU=; b=A8Xe7rtSdGNPuzytMVQVL5JidtVdFPrjSapsmYGImRnRuj5Z78QhrGDMoWJKNs6Zs2 ++wU+j/laL4/trZM8kvoElt+zOANZerAt5b1p20+bcLG9O0WIQroo721vLihguQ8v7P+ Y+QBcdNSMWckltv7xSMFzTbcE3zNQDOxD9LLjPGx7rCCJ5FvWJqLmvPMAat7NvLe8Ssq wkg7K9V80a9rN88BpZUEYH56ZGDSg81l0HnQ8wonsSnW8mvOgy+YMu5DlWCOd+zOjPF+ lj4+S3endgoXHVwo9JJ8iaPtFh3Gs7famSBP80vyHmrj+ihNWrGw+UKwxkrkA0UgxoY5 N9oQ== X-Gm-Message-State: APjAAAXibbAewX+VtIWeqbGmFf2+J+CjwzyG+1+OqbNTT7/syxZ7/XeD rbhY4IHoQ/nqbD3Emhg6f0YtMbBQNwgu6XMoQ1E= X-Google-Smtp-Source: APXvYqzSYeCpGrgUV1sTT+uCK5AF7jo31YP+WIR9jvtens+aGfx3tzHkP8CL91DSXrW0H5auyrOq+n3tLpUhajyUKPs= X-Received: by 2002:a50:91c4:: with SMTP id h4mr33264048eda.36.1573566782658; Tue, 12 Nov 2019 05:53:02 -0800 (PST) MIME-Version: 1.0 References: <20191112124420.6225-1-olteanv@gmail.com> <20191112124420.6225-7-olteanv@gmail.com> <20191112135107.GH5090@lunn.ch> In-Reply-To: <20191112135107.GH5090@lunn.ch> From: Vladimir Oltean Date: Tue, 12 Nov 2019 15:52:51 +0200 Message-ID: Subject: Re: [PATCH net-next 06/12] net: mscc: ocelot: adjust MTU on the CPU port in NPI mode To: Andrew Lunn Cc: Jakub Kicinski , "David S. Miller" , Alexandre Belloni , Florian Fainelli , Vivien Didelot , Joergen Andreasen , "Allan W. Nielsen" , Horatiu Vultur , Claudiu Manoil , netdev , Vladimir Oltean Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 12 Nov 2019 at 15:51, Andrew Lunn wrote: > > On Tue, Nov 12, 2019 at 02:44:14PM +0200, Vladimir Oltean wrote: > > From: Vladimir Oltean > > > > When using the NPI port, the DSA tag is passed through Ethernet, so the > > switch's MAC needs to accept it as it comes from the DSA master. Increase > > the MTU on the external CPU port to account for the length of the > > injection header. > > I think this is the only DSA driver which needs to do this. Generally, > the port knows it is adding/removing the extra header, and so > magically accepts bigger frames. > > Where i have seen issues is the other end, the host interface. It > sometimes drops 'full MTU' frames because the DSA header makes the > frame too big. > No, that worked out of the box because DSA adjusts the MTU of the master interface by the amount of bytes specified in the overhead of the tagger. > Reviewed-by: Andrew Lunn > > Andrew