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 7289DC46467 for ; Mon, 16 Jan 2023 09:52:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229545AbjAPJwj (ORCPT ); Mon, 16 Jan 2023 04:52:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbjAPJwJ (ORCPT ); Mon, 16 Jan 2023 04:52:09 -0500 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF94818B0F; Mon, 16 Jan 2023 01:51:56 -0800 (PST) Received: from wsk (85-222-111-42.dynamic.chello.pl [85.222.111.42]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: lukma@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 78AB884F3E; Mon, 16 Jan 2023 10:51:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1673862715; bh=AriQnM0aPmdyQ63JyxY6+PYRD6b7/e5rfRLzvkdM2R4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bJxAQW0ZM1gD7LrZPN42GA+aAVqUVuI2OaeCOqjJDwJ1Crf/M6vuC6KsPD1s/oGwL 4HjSp/ckHchnTZUiOBWLh1N6UbktVYV5FU3w82QputJaJSeez96/3B/4GEQyzz7Njn NjqZEfmnm8Z7GhacQFyvRZDZ8eP7BbXpDkt9sFBSEcIH/Qllq9FSwpqZJ7P6tY/16H 9QXCpUfgsbqtSq7ilLEfSWpKAmqKQA1sP2EtMK1VJon2qKHn7tS+qWXUxlBpotMF6X dbC0RXlUtmVI80vwHv9nYCMaMhjLRY4rwRD2LkFVgKWTUKxoR9ZgTlYYf3hSP5AanD ukFI67Z6b0/cA== Date: Mon, 16 Jan 2023 10:51:48 +0100 From: Lukasz Majewski To: "Russell King (Oracle)" , Andrew Lunn Cc: Vladimir Oltean , Eric Dumazet , Florian Fainelli , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Alexander Duyck , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/3] dsa: marvell: Provide per device information about max frame size Message-ID: <20230116105148.230ef4ae@wsk> In-Reply-To: References: <20230106101651.1137755-1-lukma@denx.de> Organization: denx.de X-Mailer: Claws Mail 3.19.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/yxWGpSSJACP3k2nu2/8Ph_X"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --Sig_/yxWGpSSJACP3k2nu2/8Ph_X Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Russell, > On Fri, Jan 06, 2023 at 11:16:49AM +0100, Lukasz Majewski wrote: > > Different Marvell DSA switches support different size of max frame > > bytes to be sent. This value corresponds to the memory allocated > > in switch to store single frame. > >=20 > > For example mv88e6185 supports max 1632 bytes, which is now > > in-driver standard value. On the other hand - mv88e6250 supports > > 2048 bytes. To be more interresting - devices supporting jumbo > > frames - use yet another value (10240 bytes) > >=20 > > As this value is internal and may be different for each switch IC, > > new entry in struct mv88e6xxx_info has been added to store it. > >=20 > > This commit doesn't change the code functionality - it just provides > > the max frame size value explicitly - up till now it has been > > assigned depending on the callback provided by the IC driver > > (e.g. .set_max_frame_size, .port_set_jumbo_size). =20 >=20 > I don't think this patch is correct. >=20 > One of the things that mv88e6xxx_setup_port() does when initialising > each port is: >=20 > if (chip->info->ops->port_set_jumbo_size) { > err =3D chip->info->ops->port_set_jumbo_size(chip, > port, 10218); if (err) > return err; > } >=20 > There is one implementation of this, which is > mv88e6165_port_set_jumbo_size() and that has the effect of setting > port register 8 to the largest size. So any chip that supports the > port_set_jumbo_size() method will be programmed on initialisation to > support this larger size. >=20 > However, you seem to be listing e.g. the 88e6190 (if I'm interpreting > the horrid mv88e6xxx_table changes correctly) Those changes were requested by the community. Previous versions of this patch were just changing things to allow correct operation of the switch ICs on which I do work (i.e. 88e6020 and 88e6071). And yes, for 88e6190 the max_frame_size =3D 10240, but (by mistake) the same value was not updated for 88e6190X. The question is - how shall I proceed?=20 After the discussion about this code - it looks like approach from v3 [1] seems to be the most non-intrusive for other ICs. > as having a maximum > frame size of 1522, but it implements this method, supports 10240, and > thus is programmed to support frames of that size rather than 1522. >=20 Links: [1] - https://lore.kernel.org/netdev/Y7M+mWMU+DJPYubp@lunn.ch/T/ Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de --Sig_/yxWGpSSJACP3k2nu2/8Ph_X Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAmPFHjQACgkQAR8vZIA0 zr1KBQgAqlq+nldC7Wy1tHVtLEpJID5+bW/abhyGBhyW9F9NAbU9AqstcJMEhuEr IPllCMvauw96YEveGfklueBgoilKvdzhAHlef1UEDSXdX5lZviWyLhiRkZYl3Qx5 OBEvpMQULe1UvZ8mhjgO/IQ09FYGpNGx5ac/IqHawIN363pyRiry7y52DUN7rbjA ubLs8TIa8/DtWJA03cMO4VfMNowMEI5vAKyNli9ojKFKSTddG7H0lvdG2TNn/ycZ tNZSDHZi0s3DfZB+wbUWfgUqmdHPIygsqAGHHPKp04i7P5IVNnRbVUGFuOLoWpfe RB7DQRIa40DfPKZ6v9f/UA+Kaw7oLw== =Yiso -----END PGP SIGNATURE----- --Sig_/yxWGpSSJACP3k2nu2/8Ph_X--