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=-0.8 required=3.0 tests=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 658D8C282DD for ; Fri, 10 Jan 2020 20:59:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4166120842 for ; Fri, 10 Jan 2020 20:59:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727159AbgAJU72 convert rfc822-to-8bit (ORCPT ); Fri, 10 Jan 2020 15:59:28 -0500 Received: from mga07.intel.com ([134.134.136.100]:49938 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726842AbgAJU72 (ORCPT ); Fri, 10 Jan 2020 15:59:28 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 12:59:27 -0800 X-IronPort-AV: E=Sophos;i="5.69,418,1571727600"; d="scan'208";a="216793425" Received: from aguedesl-mac01.jf.intel.com (HELO localhost) ([10.24.13.29]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 12:59:26 -0800 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT In-Reply-To: References: <20191127094517.6255-1-Po.Liu@nxp.com> <157603276975.18462.4638422874481955289@pipeline> <87eex43pzm.fsf@linux.intel.com> <20191219004322.GA20146@khorivan> <87lfr9axm8.fsf@linux.intel.com> <157853205713.36295.17877768211004089754@aguedesl-mac01.jf.intel.com> Subject: Re: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of traffic classes From: Andre Guedes Cc: Ivan Khoronzhuk , Murali Karicheri , Vinicius Costa Gomes , Po Liu , "alexandru.ardelean@analog.com" , "allison@lohutok.net" , "andrew@lunn.ch" , "ayal@mellanox.com" , "davem@davemloft.net" , "f.fainelli@gmail.com" , "gregkh@linuxfoundation.org" , "hauke.mehrtens@intel.com" , "hkallweit1@gmail.com" , "jiri@mellanox.com" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" , "pablo@netfilter.org" , "saeedm@mellanox.com" , "tglx@linutronix.de" , Vladimir Oltean , "simon.horman@netronome.com" , Claudiu Manoil , Alexandru Marginean , Xiaoliang Yang , Roy Zang , Mingkai Hu , Jerry Huang , Leo Li To: Vladimir Oltean Message-ID: <157868996635.61655.11306531040262384025@aguedesl-mac01.jf.intel.com> User-Agent: alot/0.8.1 Date: Fri, 10 Jan 2020 12:59:26 -0800 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vladimir, Quoting Vladimir Oltean (2020-01-10 08:02:45) > > I'm not sure about the knob 'timers (hold/release)' described in the quotes > > above. I couldn't find a match in the specs. If it refers to 'holdAdvance' and > > 'releaseAdvance' parameters described in 802.1Q-2018, I believe they are not > > configurable. Do we know any hardware where they are configurable? > > > > On NXP LS1028A, HOLD_ADVANCE is configurable on both ENETC and the > Felix switch (its default value is 127 bytes). Same as Synopsys, it is > a global setting and not per queue or per GCL entry. > RELEASE_ADVANCE is not configurable. > Regardless, I am not sure if there is any value in configuring this > knob. Remember that the minimum guard band size still needs to be > twice as large as the minimum Ethernet frame size. Not adding this knob now sounds reasonable to me too, but let's consider it in the design so we can easily add it later, in case we need it. Regards, Andre