Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761780AbYF0MVB (ORCPT ); Fri, 27 Jun 2008 08:21:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759953AbYF0MLY (ORCPT ); Fri, 27 Jun 2008 08:11:24 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:2925 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761475AbYF0MLQ (ORCPT ); Fri, 27 Jun 2008 08:11:16 -0400 Date: Thu, 26 Jun 2008 22:12:17 +0200 From: Pavel Machek To: Mayank Sharma Cc: lkml Subject: Re: Time drifting after multiple sleep/wakeup in timekeeping Message-ID: <20080626201216.GD9878@ucw.cz> References: <013B1C915F9462459242424413ABB264011AC64C@bnglmail.sirf.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <013B1C915F9462459242424413ABB264011AC64C@bnglmail.sirf.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 16 On Wed 2008-06-25 17:18:52, Mayank Sharma wrote: > Hi, > > I noticed a bug with respect to time drifting after multiple sleep/wakeup sequence. We have an embedded ARM11 based platform on which we have successfuly ported Linux. We also have a RTC on board. Hence we have implemented the read_persistent_clock() function overriding the one defined in kernel/time/timekeeping.c. What we observed was that after doing multiple sleep/wakeup sequences, the time reported by RTC and gettimeofday was drifting. After about 10 iterations the gettimeofday was lagging by about one second. Subsequently the lag only increased. > Hmm, should I look forward for linux-based gps? -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/