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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 526F2C3A59E for ; Tue, 20 Aug 2019 16:57:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26D2F214DA for ; Tue, 20 Aug 2019 16:57:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="nrExVr8U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730492AbfHTQ5f (ORCPT ); Tue, 20 Aug 2019 12:57:35 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:45810 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbfHTQ5e (ORCPT ); Tue, 20 Aug 2019 12:57:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=lPZlDP5gA+MWnoXz3gebdeb4kigYnFHrwvSUjg8QqGc=; b=nrExVr8U6g7kB0uJvGXk9qc6ZV 4u8J9jg4KL6T3pCGe8Hu6R5Mv0ltF47KSPsyHckUcMF0DGY3zvnUR49JYsowEAqiyhO3vm69+qU9C XeYjhVg7qR+f5mO/aobZOgPnRDrb+Hqk2k0jLRIWsDAIQFeCzlZmYJBQ5T0Z9V7fRsM8=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1i07Rp-0007Jd-Jw; Tue, 20 Aug 2019 18:57:29 +0200 Date: Tue, 20 Aug 2019 18:57:29 +0200 From: Andrew Lunn To: Vladimir Oltean Cc: Mark Brown , Hubert Feurstein , mlichvar@redhat.com, Richard Cochran , Florian Fainelli , linux-spi@vger.kernel.org, netdev Subject: Re: [PATCH spi for-5.4 0/5] Deterministic SPI latency with NXP DSPI driver Message-ID: <20190820165729.GQ29991@lunn.ch> References: <20190818182600.3047-1-olteanv@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > - Ethernet has support for hardware timestamping True, but not all drivers support it. Marvell switches are often combined with Marvell MACs. None of the Marvell MAC drivers, mv643xx, mvneta, mvpp2 or octeontx2 support hardware timestamping. My guess is, the hardware probably supports it, but nobody has taken the time to writing the driver code. FEC does have PTP support, but what does it look like in general? Are Marvell drives the exception, or the norm? What we have been talking about in this thread, adding timestamp calls at various places, is simple, compared to adding driver code to a number of MAC drivers. We can get a lot of 'bang for our buck' with time stamps, it is easy to copy to other drivers, you don't need a good knowledge of the hardware, datasheet, etc. So if we can get this accepted, we should try to do it. You can always come back later and add your full hardware solution. Andrew