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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 3F50FC433DF for ; Fri, 16 Oct 2020 15:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3FE120848 for ; Fri, 16 Oct 2020 15:56:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Oe1GsO4q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410530AbgJPP4t (ORCPT ); Fri, 16 Oct 2020 11:56:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408157AbgJPP4s (ORCPT ); Fri, 16 Oct 2020 11:56:48 -0400 Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DE29C061755; Fri, 16 Oct 2020 08:56:48 -0700 (PDT) Received: by mail-ed1-x543.google.com with SMTP id t21so2969111eds.6; Fri, 16 Oct 2020 08:56:48 -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=/6eJb3d/LH1w9U+JGdalk+l2zLyd0Hh/mR0rroG5prU=; b=Oe1GsO4qAOTblXYzhEN+nYK7SJWlNrdKpAaOFmZ3+qHZPSlYVUxy2ohAk6kMhnal51 fdkzbCzM7AfnyPgnB0eV6Y7F93lLph/CCOxBKu9768v4Q6OE1l10LIyxwY0G5kSVbSPY 7mVqrodaImSyxdDyRUwpsQAq6iZgJ7GNg03duhV0VgZBgk6XQqc3S6zmkQprThgkdEco R2ap+22LzK0SkgqxC1WSRcB2eYeUjk3fXyJwAxlfR8GSo7qIkwhXmdu3xlQuBiWlwfDG xe0GUmojrzuTW6/UGAAEB4Dx7C8/vfcQTv7X2znGNTqB6a6TKs4PJl6gz7RQjFD2dQDV Re9Q== 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=/6eJb3d/LH1w9U+JGdalk+l2zLyd0Hh/mR0rroG5prU=; b=qqwbiu385u8+FfWdRBNXcIfTXJvqtIbt7NjCm2BGaRV2c5ainlGUKm48HdAAAKTx0e hJkwdMydd/BsQrimF01ypSsOAXE8nGQ+8bxoTKngFZRv9I1bhqGsXwFF3WU609D7lGhc eY7DWaQn6+zkKcXj3cmZzyPrGIfp+4V5HzSTSIplAXMCBkNTOKEhyH0MHYzscy0gR7M/ fVVhMNR+6d7ZLLMXOUdsWqew7nI8GMelO9yASdXWy69L4UkMUYc2OfDS7TDglpAMAg59 4G7pDzTBi602mo79PSbqo79eweZWk6QAqyXLlfo+SY0TjWACDF/EptxQSzNStbYfpAau E4nA== X-Gm-Message-State: AOAM530BFmY6e88mQ2u6oa5D7SkFfhwvPea4fU6lUmvw4TNZiF67vbM6 1R3QC5f3w7QT2ueABdLnuSc= X-Google-Smtp-Source: ABdhPJwQRMmXfizi2zx4WaAk+ytCAGe2YF6JcYioAUlXSjuUK6Z4gWryF0tQ5WvrgWeqr/7O7umS3A== X-Received: by 2002:a50:fa42:: with SMTP id c2mr4956878edq.282.1602863807002; Fri, 16 Oct 2020 08:56:47 -0700 (PDT) Received: from skbuf ([188.26.174.215]) by smtp.gmail.com with ESMTPSA id rs18sm1958606ejb.69.2020.10.16.08.56.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Oct 2020 08:56:46 -0700 (PDT) Date: Fri, 16 Oct 2020 18:56:45 +0300 From: Vladimir Oltean To: Christian Eggers Cc: Kurt Kanzenbach , Woojung Huh , Andrew Lunn , Vivien Didelot , Florian Fainelli , Microchip Linux Driver Support , "David S . Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] net: dsa: ksz: fix padding size of skb Message-ID: <20201016155645.kmlehweenqdue6q2@skbuf> References: <20201014161719.30289-1-ceggers@arri.de> <4467366.g9nP7YU7d8@n95hx1g2> <20201016090527.tbzmjkraok5k7pwb@skbuf> <1655621.YBUmbkoM4d@n95hx1g2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1655621.YBUmbkoM4d@n95hx1g2> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 16, 2020 at 02:44:46PM +0200, Christian Eggers wrote: > Machine: > - ARMv7 (i.MX6ULL), SMP_CACHE_BYTES is 64 > - DSA device: Microchip KSZ9563 (I am currently working on time stamping support) I have a board very similar to this on which I am going to test. > Last, CONFIG_SLOB must be selected. Interesting, do you know why? > 3. "Manually" unsharing in dsa_slave_xmit(), reserving enough tailroom > for the tail tag (and ETH_ZLEN?). Would moving the "else" clause from > ksz_common_xmit() to dsa_slave_xmit() do the job correctly? I was thinking about something like that, indeed. DSA knows everything about the tagger: its overhead, whether it's a tail tag or not. The xmit callback of the tagger should only be there to populate the tag where it needs to be. But reallocation, padding, etc etc, should all be dealt with by the common DSA xmit procedure. We want the taggers to be simple and reuse as much logic as possible, not to be bloated.