From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752942Ab0IIMvQ (ORCPT ); Thu, 9 Sep 2010 08:51:16 -0400 Received: from www.tglx.de ([62.245.132.106]:39271 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751438Ab0IIMvN (ORCPT ); Thu, 9 Sep 2010 08:51:13 -0400 Date: Thu, 9 Sep 2010 14:50:57 +0200 (CEST) From: Thomas Gleixner To: Richard Cochran cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, john stultz Subject: Re: [PATCH 0/2] [RFC] posix clock tuning In-Reply-To: <20100909122156.GA2823@riccoc20.at.omicron.at> Message-ID: References: <20100909122156.GA2823@riccoc20.at.omicron.at> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Sep 2010, Richard Cochran wrote: > From my point of view, the discussion is going round in circles. There Sorry for coming late and adding more to the general confusion. :) > seems to be agreement that supporting PTP hardware clocks is a good > idea. The objections seem to be about the form of the API. In general, > there are three avenues. > > 1. character device (like hpet) > 2. posix clock api > 3. sysfs > > Or possibly some combination of the three. I fail to see the requirement for any of those. Either the hardware clock is suitable as a clocksource for general consumption, then it should just be used as a clock source. If it's not - e.g. because it's too slow to access - then it just should serve as a reference in the NTP style and steer the timekeeping into sync. As I said in the other reply, I know that you want a global synchronized clock aside of CLOCK_REALTIME, but that's an easy to solve problem. See my other reply for details. Thanks, tglx