Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752643Ab0H0M2S (ORCPT ); Fri, 27 Aug 2010 08:28:18 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:59094 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752321Ab0H0M2Q (ORCPT ); Fri, 27 Aug 2010 08:28:16 -0400 Date: Fri, 27 Aug 2010 13:45:32 +0100 From: Alan Cox To: Richard Cochran Cc: john stultz , Arnd Bergmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree-discuss@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, Krzysztof Halasa , Rodolfo Giometti Subject: Re: [PATCH 1/5] ptp: Added a brand new class driver for ptp clocks. Message-ID: <20100827134532.6fbb40fb@lxorguk.ukuu.org.uk> In-Reply-To: <20100827110855.GA11657@riccoc20.at.omicron.at> References: <1282176776.2865.100.camel@localhost.localdomain> <20100819055518.GA4084@riccoc20.at.omicron.at> <201008191428.04546.arnd@arndb.de> <20100819153847.GA10695@riccoc20.at.omicron.at> <1282594899.3111.358.camel@localhost.localdomain> <20100827110855.GA11657@riccoc20.at.omicron.at> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1172 Lines: 30 > > So if the clock_adjtime interface is needed, it would seem best for it > > to be generic enough to support not only PTP, but also the NTP kernel > > PLL. > > For the proposed clock_adjime, what else is needed to support clock > adjustment in general? Multiple PLLs, at least with containers and certain classes of system you want different containers in different timespaces, especially when doing high precision stuff where you need your system tracking say a local master clock for syncing musical instruments and sound events while tracking other clocks like NTP for general system time. > I don't mind making the interface generic enough to support any > (realistic) conceivable clock adjustment scheme, but beyond the > present PTP hardware clocks, I don't know what else might be needed. Put the clock type in the new fields. It becomes u16 clock_type; [clock type specific data] saves having to guess. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/