From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-4.sys.kth.se (smtp-4.sys.kth.se [130.237.48.193]) by dpdk.org (Postfix) with ESMTP id E5FC31559 for ; Tue, 4 Sep 2018 16:26:28 +0200 (CEST) Received: from smtp-4.sys.kth.se (localhost.localdomain [127.0.0.1]) by smtp-4.sys.kth.se (Postfix) with ESMTP id 87D032B85; Tue, 4 Sep 2018 16:26:28 +0200 (CEST) X-Virus-Scanned: by amavisd-new at kth.se Received: from smtp-4.sys.kth.se ([127.0.0.1]) by smtp-4.sys.kth.se (smtp-4.sys.kth.se [127.0.0.1]) (amavisd-new, port 10024) with LMTP id NVz14-TD6_qS; Tue, 4 Sep 2018 16:26:27 +0200 (CEST) Received: from exdb01.ug.kth.se (unknown [192.168.32.111]) by smtp-4.sys.kth.se (Postfix) with ESMTPS id 327C2293B; Tue, 4 Sep 2018 16:26:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kth.se; s=default; t=1536071187; bh=cza9xkAaM6zAvC5iaWuZOf6Cl98WVLOTxq5Ps5vTans=; h=From:To:CC:Subject:Date; b=W/1CzIHCo+Hqq1OTXweGbfNwQmCLOe2Q3oE7jPz6PqVbRLtcuxKx6oaSQSpmP6/BG TFu6rnylzrD78LWnjHYsWWgmTvTTWNYQFPSzXOdEMLuPZF6n9E+mkylUrnKj/rtF8X fWcPHf/V5SIe6dXZIiiEMq11tZ0K2b3eg1/sZdA8= Received: from exdb05.ug.kth.se (192.168.32.115) by exdb01.ug.kth.se (192.168.32.111) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Tue, 4 Sep 2018 16:26:03 +0200 Received: from exdb05.ug.kth.se ([192.168.32.115]) by exdb05.ug.kth.se ([192.168.32.115]) with mapi id 15.00.1367.000; Tue, 4 Sep 2018 16:26:03 +0200 From: Tom Barbette To: "dev@dpdk.org" CC: "shahafs@mellanox.com" , "yskoh@mellanox.com" , "john.mcnamara@intel.com" , "marko.kovacevic@intel.com" Thread-Topic: MLX5 should define the timestamp field in the doc Thread-Index: AQHURFrn477t1+S0lkKGIf1HTd0m9A== Date: Tue, 4 Sep 2018 14:26:02 +0000 Message-ID: <1536071162684.44442@kth.se> Accept-Language: fr-FR, sv-SE, en-US Content-Language: fr-FR X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [130.237.202.15] MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-dev] MLX5 should define the timestamp field in the doc X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Sep 2018 14:26:29 -0000 Hi all, As far as I know, MLX5 is the only driver to support hardware timestamping. It would be great to update the doc to explain what the hardware timestamp = is supposed to be. If it's nanoseconds, then just a shift regarding system = time is enough ? Does it also need a multiplication? Can we query that from= hardware? Or provide a piece of code to be used. As it, the feature is use= less... It would be interesting to normalize the hardware timestamping. I guess for= any driver, an offset and a multiplication(shift+multiplier eventually) wo= uld be enough, and the API should be updated to provide a function to conve= rt a hardware timestamp to software (or that should be part of the driver a= nd done automatically if offloading is enabled?) and probably one to initia= lize the time, much like the Linux one at https://elixir.bootlin.com/linux/= v4.18.5/source/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c#L488 . Thanks, Tom ?