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 D329EECAAD8 for ; Wed, 21 Sep 2022 11:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229944AbiIULqb (ORCPT ); Wed, 21 Sep 2022 07:46:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229879AbiIULq2 (ORCPT ); Wed, 21 Sep 2022 07:46:28 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 385998709D; Wed, 21 Sep 2022 04:46:27 -0700 (PDT) From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1663760785; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+h5OB886Dzz/hwPi6y3bnH4tBaZnTz6gSDGhoyX42fM=; b=EKqm+o89UidMbgUhAt1wAmGnHDv5RQ2OoSdOS6hA9VZWTWvQFLRPfXeHzxEpGIwAbZBIu3 UnTdgA5cyyWt0y3rLbDCVWY3GXQmgGtDKBlmawzYzDus9UHXYQQA4uc2MfKxqO/bBbcjCp P609VGxyP/EBJqKokiON4shumesBkVFHh+/uTo96yHg7pO+eMZSvdEqwQDkxZIu0ID1ems 9KhdFvpTDK7B9FwnS+qx+1XDhNPIvGhG+0btFIOOFmJCXqKbSVbdcCoXrM1GzLKJ8UTyOo +73x9Z5sO/X/mZSxPU1TxF+8frBnuoeAr1imqodzHBAxgWuOAxlwTFZPyxH2EQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1663760785; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+h5OB886Dzz/hwPi6y3bnH4tBaZnTz6gSDGhoyX42fM=; b=281BLSmmIT4ZtfMUGMyANtLWIeS0k+Bg/wnoPYtsL4nsgBRSaXkknrVm0/YyEPy99a9JbN Ai5EVTGkRku4MsAA== To: Vladimir Oltean Cc: "netdev@vger.kernel.org" , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Xiaoliang Yang , Rui Sousa , Claudiu Manoil , Alexandre Belloni , "UNGLinuxDriver@microchip.com" , Andrew Lunn , Vivien Didelot , Florian Fainelli , Michael Walle , Vinicius Costa Gomes , Maxim Kochetkov , Colin Foster , Richie Pearn , Vladimir Oltean , Jesse Brandeburg , Tony Nguyen , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Jamal Hadi Salim , Cong Wang , Jiri Pirko , Gerhard Engleder , Grygorii Strashko , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net-next 08/13] net: dsa: hellcreek: deny tc-taprio changes to per-tc max SDU In-Reply-To: <20220921112916.umvtccuuygacbqbb@skbuf> References: <20220914153303.1792444-1-vladimir.oltean@nxp.com> <20220914153303.1792444-9-vladimir.oltean@nxp.com> <87a671bz8e.fsf@kurt> <20220914184051.2awuutgr4vm4tfgf@skbuf> <87r10dxiw5.fsf@kurt> <20220915115925.zujsneox4jqzod2g@skbuf> <87bkr9m0nn.fsf@kurt> <20220921112916.umvtccuuygacbqbb@skbuf> Date: Wed, 21 Sep 2022 13:46:22 +0200 Message-ID: <878rmdlzld.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed Sep 21 2022, Vladimir Oltean wrote: > On Wed, Sep 21, 2022 at 01:23:24PM +0200, Kurt Kanzenbach wrote: >> On Thu Sep 15 2022, Vladimir Oltean wrote: >> > On Thu, Sep 15, 2022 at 08:15:54AM +0200, Kurt Kanzenbach wrote: >> >> > So the maxSDU hardware register tracks exactly the L2 payload size,= like >> >> > the software variable does, or does it include the Ethernet header = size >> >> > and/or FCS? >> >>=20 >> >> This is something I'm not sure about. I'll ask the HW engineer when h= e's >> >> back from vacation. >> > >> > You can also probably figure this out by limiting the max-sdu to a val= ue >> > like 200 and seeing what frame sizes pass through. >>=20 >> So, configured to 128 and 132 bytes (including VLAN Ethernet header) is >> the maximum frame size which passes through. > > Frame size means MAC DA + MAC SA + VLAN header + Ethertype + L2 payload, > and without FCS, right? Yes. > > Because max_sdu 128 only counts the L2 payload, so the maximum frame > size that passes should be 142 octets, or 146 octets with VLAN. Ok, i see. So, for 128 max-sdu we should end up with something like this in the prio config register: schedule->max_sdu[tc] + VLAN_ETH_HLEN - 4 Thanks, Kurt --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJHBAEBCgAxFiEEvLm/ssjDfdPf21mSwZPR8qpGc4IFAmMq+Y4THGt1cnRAbGlu dXRyb25peC5kZQAKCRDBk9HyqkZzgsQMD/9WRNdSk5bgkVm3cV5TvCmIaW9J5DID qcw8at7AMpg33GRleT0ovLrCYdP/jpuG1bL9ODgs6hB9WG/sxTae0ElfWpiwQdpx 7F/5pImKfg3EXARHVULww3L63xFYgdeoYHyqjNYscWtxCtTS+uO6paksZBpga6Gf zYM0p/W0fIPAjBsvzdI3+BCy42ut6K2iwMGvD9YZ7zbHr8RdGtnW1+gsfzzuu/Iz 15erg05SpFZGTNYpSGJ4KZAU09IvtjUqVA9m7DAunQaRvq7def7OSrtb+Plvbym2 wz6rU16pULDvm1i9e7lAwXAmaGu34H/Pb7xp0q9k14mxrztmrouRc22XGvI328b0 eAPHDSZcRyNgSG6GEvjR8jDMwg+Zrp+/dgtnNjIj+lOvSKrBAsUAfyN2UWfvCU5Y YfV1r5sa/0rfUE3CvxgTwnFiCk36F5DO+n9kWiCdNqST6bsibLBuzdZvoBRcuAu/ /fA8VCfX+xeRTNkHyWzuoHHwgfmU74vbmL4P4poQZeY5Sallr7LXzIh9OYR+3NFh iqd7xEgSVdT1OZsgaXI4trWzvr1dlWlsx22FANwMPL8/ar80HdPsU5eRKm1+i/mJ 3iVcakxcj4GbQBHuSaerIAJexJ02luKwrlxJn+i0Xll+N/+FkqzQzuD5NNhjJTDk Pj9SEV4COxIFEw== =ywiY -----END PGP SIGNATURE----- --=-=-=--