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 BEF03C678D4 for ; Fri, 3 Mar 2023 13:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229892AbjCCNMy (ORCPT ); Fri, 3 Mar 2023 08:12:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229563AbjCCNMx (ORCPT ); Fri, 3 Mar 2023 08:12:53 -0500 Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1146D10F0 for ; Fri, 3 Mar 2023 05:12:50 -0800 (PST) Received: (Authenticated sender: kory.maincent@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id B0F4D40008; Fri, 3 Mar 2023 13:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1677849169; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AMNOjpgLvxddvR7qOB5Du1EiUOiGDc9UQlYsmboXaHQ=; b=pfsBTnwpjwcM61jFyMeZD6IInl0x/+LNflQLYEMH+JDo421N3Yn9LxIJn9N88wvAsa1sWT mJU2fsaMyV7H7tjV9Ns0GtpE/ivaE445R1vjq8gN7iVdlRQis/SUpqrsFxTbz9iK4TSwo+ BwToQR3toSfaWTXgTxOd5SJnPXLhWR6NsSn05uDY6ANFmvuvxDETlnUcFnyl8+p0oac18y zbnXeAL1/lWHyLXUdMgNMogX5CAFF2Bq4xJG3c7WWqNkosUJJ1VzkEqSovuIMNagK5QVtO r3zlJ3rb3D22cMRx7KkzVgzJjLkdJXZ1viF2NbQfmWazd0CwhVrkkoO7k2u+9Q== Date: Fri, 3 Mar 2023 14:12:47 +0100 From: =?UTF-8?B?S8O2cnk=?= Maincent To: Jakub Kicinski Cc: "Russell King (Oracle)" , Richard Cochran , andrew@lunn.ch, davem@davemloft.net, f.fainelli@gmail.com, hkallweit1@gmail.com, netdev@vger.kernel.org, Thomas Petazzoni , Maxime Chevallier Subject: Re: [PATCH RFC net-next] net: phy: add Marvell PHY PTP support [multicast/DSA issues] Message-ID: <20230303141247.4acd6863@kmaincent-XPS-13-7390> In-Reply-To: <20230302092320.6ee8eb6d@kernel.org> References: <20230228141630.64d5ef63@kmaincent-XPS-13-7390> <20230228142648.408f26c4@kernel.org> <20230228145911.2df60a9f@kernel.org> <20230301170408.0cc0519d@kmaincent-XPS-13-7390> <20230302084932.4e242f71@kernel.org> <20230302180616.7bcfc1ef@kmaincent-XPS-13-7390> <20230302092320.6ee8eb6d@kernel.org> Organization: bootlin X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 2 Mar 2023 09:23:20 -0800 Jakub Kicinski wrote: > Do you happen to have a datasheet for MACB? The time stamping > capability is suspiciously saved in a variable called hw_dma_cap > which may indicate it's a DMA time stamp not a true PTP stamp. >=20 > Quite a few NICs/MACs support DMA time stamps because it's far=20 > easier to take the stamp where the descriptor writing logic is > (DMA block) than take it at the end of the MAC and haul it all=20 > the way thru the pipeline back to the DMA block. I don't have the datasheet but indeed you seem to have right. From the supp= ort commit message:=20 > Time stamps are obtained from the dma buffer descriptors I suppose it is less precise as using true PTP stamp as it is an hardware b= lock further. Is that right? Regards, K=C3=B6ry