From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AB40BE5F for ; Fri, 12 May 2023 10:29:36 +0000 (UTC) Received: from EUR05-DB8-obe.outbound.protection.outlook.com (mail-db8eur05on2067.outbound.protection.outlook.com [40.107.20.67]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DEE9213B for ; Fri, 12 May 2023 03:29:20 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=n67ORYbUYK+1QMCtLhJOUCr1HXrFkdSckqIXg4b8ZCdj5iVjO6ZxZPX8tF+jtfG+yr/hM+DhIsd3F0glTWcAdZ8mPJDtz+uurtedrgjV61HimE/oc0jkise77hLH0nuz4w8O2MuO0vhRjou71UPZVTVvQQ6vRcbOhn0G8/j1M/gQ9CS/6E/ZlpNlqNBsQISApy3MjPiwYzlDQwb1UnhWu8yCjOEQj8wTUhT/S5mbRZTovydtQXoVWvuwL1o/JmDnM9s/0xkLv34DRGRFxuVF9fozIsYznC50TMeKLUATMM+aoF+bajLc74vhM3lrPOa7/7i/e3JYe3+o4PH/BiNagw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=N/Uj5ns4r8gSyWJNVqkCyrrhFDODe8aBN7/Q671jAYg=; b=N7sGaMooDw4wUtXpICOLkFiH+uE2QfE6gALIwKtcWGxiSCa221Kv4dzjF4mCYdHYxBrSzsRpA8Og4OzY6Fj+dqFqWLSryfIYGZ/+TrefYfnIM4XZTmjwO7nOzTZw4CNCRoci/jjwK2XOCDPm7qozYV5caBcmT2ibHx+OF7w9+IR188DEvFMBZ3QhoCgTD7lG7BAyp5QByImeWw1rdusAFiWuBd4cYnctVp+RguJxxrDoeqia8fDkM5Onl+3nBT393cEYa8Y7o629ZtodPUmP9DDSNb3b4ZMUue57xTpdTe4iaMNH+yMkf4YbtEVIQDgVnwozJDOxjXH4cnZJgikosQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=N/Uj5ns4r8gSyWJNVqkCyrrhFDODe8aBN7/Q671jAYg=; b=So0Z3mEXl7MAl89X9zdERd7AlyWD1cU2lKW1YQ6kX0IVZdq9VfEZ0KmuctJgMmyP817p6uqAMa8A1fV1hpx/2BfX5NKWho/LHfxAjYbOGU9qoE9gC7XPVlPLkcm2QcgU3hpZYnfU6JPUtaHc9/HI3X8k+Ve0fiPAdtqlRnt3/IA= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from DB8PR04MB6459.eurprd04.prod.outlook.com (2603:10a6:10:103::19) by DB9PR04MB9626.eurprd04.prod.outlook.com (2603:10a6:10:309::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6387.21; Fri, 12 May 2023 10:29:17 +0000 Received: from DB8PR04MB6459.eurprd04.prod.outlook.com ([fe80::c157:e89a:e0f5:f85]) by DB8PR04MB6459.eurprd04.prod.outlook.com ([fe80::c157:e89a:e0f5:f85%6]) with mapi id 15.20.6363.033; Fri, 12 May 2023 10:29:16 +0000 Date: Fri, 12 May 2023 13:29:11 +0300 From: Vladimir Oltean To: Jakub Kicinski Cc: "Russell King (Oracle)" , Andrew Lunn , =?utf-8?B?S8O2cnk=?= Maincent , netdev@vger.kernel.org, glipus@gmail.com, maxime.chevallier@bootlin.com, vadim.fedorenko@linux.dev, richardcochran@gmail.com, gerhard@engleder-embedded.com, thomas.petazzoni@bootlin.com, krzysztof.kozlowski+dt@linaro.org, robh+dt@kernel.org Subject: Re: [PATCH net-next RFC v4 2/5] net: Expose available time stamping layers to user space. Message-ID: <20230512102911.qnosuqnzwbmlupg6@skbuf> References: <20230406173308.401924-1-kory.maincent@bootlin.com> <20230406173308.401924-3-kory.maincent@bootlin.com> <20230406184646.0c7c2ab1@kernel.org> <20230511203646.ihljeknxni77uu5j@skbuf> <54e14000-3fd7-47fa-aec3-ffc2bab2e991@lunn.ch> <20230511210237.nmjmcex47xadx6eo@skbuf> <20230511150902.57d9a437@kernel.org> <20230511230717.hg7gtrq5ppvuzmcx@skbuf> <20230511161625.2e3f0161@kernel.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230511161625.2e3f0161@kernel.org> X-ClientProxiedBy: AS4P191CA0016.EURP191.PROD.OUTLOOK.COM (2603:10a6:20b:5d9::11) To DB8PR04MB6459.eurprd04.prod.outlook.com (2603:10a6:10:103::19) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DB8PR04MB6459:EE_|DB9PR04MB9626:EE_ X-MS-Office365-Filtering-Correlation-Id: 8c7a4c16-a88d-4a8d-fa3d-08db52d3bd0b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DB8PR04MB6459.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(7916004)(4636009)(346002)(39860400002)(376002)(136003)(396003)(366004)(451199021)(6916009)(2906002)(66476007)(83380400001)(4744005)(6486002)(6666004)(478600001)(66946007)(66556008)(8936002)(6506007)(1076003)(9686003)(26005)(6512007)(186003)(7416002)(8676002)(316002)(4326008)(41300700001)(5660300002)(54906003)(44832011)(86362001)(38100700002)(33716001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?BzUsjLTvhzOgUE1X9KOjXEsjcmf3rfHAzCVywSL1y3DZnWkIrUi6ZENZgOnV?= =?us-ascii?Q?OpznY81Ef/e/T3VRBL6J1z4VXOc0nX6PEUmRvcXBbc/yQ2ltFAbsYPz1PDD3?= =?us-ascii?Q?ssbJihsSx5hTqZXdbQPcPURjttmf0I31nzj5MLn0K7QlKGk8sS27bF3y/Dq7?= =?us-ascii?Q?aGz/Pl6TbP8vBDxeTPooo0v3BkbaNHO9dWJvSx66KfDTUhuFMZyhFywBzFiK?= =?us-ascii?Q?caIhSqRQ25HmkaJ5xSBzPtKuV8RRMcuSXAQptx2o25Ef1cuyeicEISjQdniv?= =?us-ascii?Q?it/BXG2l/Kid7c6Z4bTFvKCkX4va7L23NIHBhF96BRlkRc9CiZ/Pv31oyZdN?= =?us-ascii?Q?Mmr5LZWhPR/zaj9aQ+JMK+enmc3mJL4LRiU3smUb9YhZnQT86YNjwikRPA0J?= =?us-ascii?Q?2oTmW+PFcCbG3abGoD/HLjTHRScNfYxRt87E02LekfS47NGEYKr0fLjwrt+9?= =?us-ascii?Q?8xI5TWrLpv51qqUQ98hjOV9xpsUc0KwRQJEIEA1N0VoDBWn7a129PKlyV1b5?= =?us-ascii?Q?brkR3U5kTt2Ca1FtBAV5yZ+HPaNhDw/lHP+x+/sjjmWnVd1EvTjZz5E9qdfG?= =?us-ascii?Q?H0B2oSBI2XCDbC4PTiSazCe5BJXxCwyW+9Tzj1/dicQR8qzAv2E1IBhN6tEC?= =?us-ascii?Q?aZVa6fmhyWjwSdHmm9llngznqnX1tY9TCPs0DdasBwTeYZdj/pIH2lYMIPOl?= =?us-ascii?Q?ISQNHUaWNj/qljyxjVei1fx5EtnOq+ABCytf7XGySG102HJfAqEhLVC1hk9h?= =?us-ascii?Q?BptENnYJyT5h0nHrL58o93t6mRvvTTxf5cp8/bHINQmGncvSUZbsulH7oGqr?= =?us-ascii?Q?ydIpAI7wjHv90RxbO6DbvCjbFlT2yU48m5fSZNA3rwnMjh9b1/abuHuLAbZ2?= =?us-ascii?Q?94gvipumNWTG63RKLqpllJwkNvx+40PYyjbTgumsuMIF4tGxbWGz3+yjHvvs?= =?us-ascii?Q?uYMuZmX9I3Cqp9C74X0I4Sx8sEPYZG6bzpRjM7+yfnWTo7Socjw/jOnJSWlh?= =?us-ascii?Q?lZJavMKpMUgEPZbeJ0XPgl5tGR4jqnxi6MiBCaYgnERIPGoM99Zn52ntNEGl?= =?us-ascii?Q?6oalwaD+37HwOagKWSKpcnZfLlVCoKaqkR9T9A5/NR/x3Rt2gKEuz41qE0Xj?= =?us-ascii?Q?fgBaV6w9t5N4jUfpW5gKdU1Qi6gdyonwj7XOy4mhEXhAa77qBnKngsHIkPBf?= =?us-ascii?Q?9ufGC+Cr6q6NAzUz8oB4Sjgw+8q5Bk32tbKOn8+6Ew5KdY4Bal5ItOHle1Ts?= =?us-ascii?Q?VTZ/kDxbjMgoDFvZRWmeD9H/i+gdQjLR7iWJTjRmzVKhiREbxA19qRSehVRv?= =?us-ascii?Q?5a9fI3QmdlDrTSBcrcWjVjOpavnNUwQEx6ENPhctFqtLZfallfDdelHcFsrP?= =?us-ascii?Q?xwU+7TOrbiUkPR1IlKSiwEN0On/EMeznU6p3FOMXoZIxoiueu2WA2ZD44kXp?= =?us-ascii?Q?U5HeisZgpMEL5zaJttQyX2YOFcFAFMc8O8+7LmhLksafbV68EZzovLEIyRg5?= =?us-ascii?Q?AojIiD4jf7pSkMW/DHYdqZMpdxpeS1EUCyDJvFTEX5YERqgKt8gaYR2QVyYU?= =?us-ascii?Q?hPIHotA8rT/2HtXH7KDD/dQDV7LHKEdhFF+Rz49N0Oml07vs9P9OaiJgNvS8?= =?us-ascii?Q?GQ=3D=3D?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8c7a4c16-a88d-4a8d-fa3d-08db52d3bd0b X-MS-Exchange-CrossTenant-AuthSource: DB8PR04MB6459.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 May 2023 10:29:16.8462 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: KakgVnWzMgmUdszpyzF+etpuppDUffVGCr4S+/c8h1kDiosriuAgSQTWfH5FO4MNXRoU+4KWgkdD8WT3SFFWIw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB9PR04MB9626 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Thu, May 11, 2023 at 04:16:25PM -0700, Jakub Kicinski wrote: > > I mean, I can't ignore the fact that there are NICs that can provide > > 2-step TX timestamps at line rate for all packets (not just PTP) for > > line rates exceeding 10G, in band with the descriptor in its TX > > completion queue. I don't want to give any names, just to point out > > that there isn't any inherent limitation in the technology. > > Oh, you should tell me, maybe off-list then. 'Cause I don't know any. I hope the examples given in private will make you reconsider the validity of my argument about DMA timestamps.