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=-3.8 required=3.0 tests=BAYES_00, 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 34A5BC433E0 for ; Thu, 21 Jan 2021 16:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECCA7206D8 for ; Thu, 21 Jan 2021 16:30:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732839AbhAUQYE (ORCPT ); Thu, 21 Jan 2021 11:24:04 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:52774 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731930AbhAUQX1 (ORCPT ); Thu, 21 Jan 2021 11:23:27 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1l2cjF-001r0Z-GH; Thu, 21 Jan 2021 17:22:37 +0100 Date: Thu, 21 Jan 2021 17:22:37 +0100 From: Andrew Lunn To: Richard Cochran Cc: Russell King - ARM Linux admin , Heiner Kallweit , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org Subject: Re: [PATCH net-next] net: ethtool: allow MAC drivers to override ethtool get_ts_info Message-ID: References: <20210114125506.GC3154@hoboy.vegasvil.org> <20210114132217.GR1551@shell.armlinux.org.uk> <20210114133235.GP1605@shell.armlinux.org.uk> <20210114172712.GA13644@hoboy.vegasvil.org> <20210114173111.GX1551@shell.armlinux.org.uk> <20210114223800.GR1605@shell.armlinux.org.uk> <20210121040451.GB14465@hoboy.vegasvil.org> <20210121102738.GN1551@shell.armlinux.org.uk> <20210121150611.GA20321@hoboy.vegasvil.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210121150611.GA20321@hoboy.vegasvil.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Jan 21, 2021 at 07:06:11AM -0800, Richard Cochran wrote: > On Thu, Jan 21, 2021 at 10:27:38AM +0000, Russell King - ARM Linux admin wrote: > > As I already explained to you, you can *NOT* use kernel configuration > > to make the choice. ARM is a multi-platform kernel, and we will not > > stand for platform choices dictated by kernel configuration options. > > This has nothing to do with ARM as a platform. The same limitation > applies to x86 and all the rest. > > The networking stack does not support simultaneous PHY and MAC time > stamping. Hi Richard And this appears to be the crux of the problem. You say PHY timestamping is exotic. I would disagree with that. Many Marvell PHYs support it, using similar hardware as to what is in the Marvell DSA switches. The Aquantia PHYs support it, but have no driver support at the moment. Microsemi PHYs have driver support for it. There are Broadcom PHYs with the needed hardware. So does some of the Qualcom PHYs. There are automotive T1 PHYs with PTP hardware support. Some Realtek devices have the hardware. There is a growing interesting in PTP, the number of drivers keeps going up. The likelihood of MAC/PHY combination having two timestamping sources is growing all the time. So the stack needs to change to support the selection of the timestamp source. Andrew