Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754164Ab0KTQ1g (ORCPT ); Sat, 20 Nov 2010 11:27:36 -0500 Received: from 81-174-11-161.staticnet.ngi.it ([81.174.11.161]:48405 "EHLO mail.enneenne.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751895Ab0KTQ1f (ORCPT ); Sat, 20 Nov 2010 11:27:35 -0500 Date: Sat, 20 Nov 2010 17:27:18 +0100 From: Rodolfo Giometti To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, "Nikita V. Youshchenko" , linuxpps@ml.enneenne.com, Andrew Morton , John Stultz , Thomas Gleixner Message-ID: <20101120162718.GF13356@enneenne.com> Mail-Followup-To: Alexander Gordeev , linux-kernel@vger.kernel.org, "Nikita V. Youshchenko" , linuxpps@ml.enneenne.com, Andrew Morton , John Stultz , Thomas Gleixner References: <2783e9e632882e211abde03e9b4ad89a336fd167.1290087480.git.lasaine@lvk.cs.msu.su> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2783e9e632882e211abde03e9b4ad89a336fd167.1290087480.git.lasaine@lvk.cs.msu.su> Organization: GNU/Linux Device Drivers, Embedded Systems and Courses X-PGP-Key: gpg --keyserver keyserver.linux.it --recv-keys D25A5633 User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: 192.168.32.37 X-SA-Exim-Mail-From: giometti@enneenne.com Subject: Re: [PATCHv4 13/17] ntp: add hardpps implementation X-SA-Exim-Version: 4.2.1 (built Wed, 25 Jun 2008 17:14:11 +0000) X-SA-Exim-Scanned: Yes (on mail.enneenne.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1574 Lines: 33 On Thu, Nov 18, 2010 at 07:01:06PM +0300, Alexander Gordeev wrote: > This commit adds hardpps() implementation based upon the original one > from the NTPv4 reference kernel code from David Mills. However, it is > highly optimized towards very fast syncronization and maximum stickness > to PPS signal. The typical error is less then a microsecond. > To make it sync faster I had to throw away exponential phase filter so > that the full phase offset is corrected immediately. Then I also had to > throw away median phase filter because it gives a bigger error itself > if used without exponential filter. > Maybe we will find an appropriate filtering scheme in the future but > it's not necessary if the signal quality is ok. This patch (and follows) adds a new functionality to PPS subsystem, so let me suggest to you splitting in two parts this patch set: a first patch set who fixes up the current PPS implementation, and a second patch set who adds kernel consumer (and follows). Ciao, Rodolfo -- GNU/Linux Solutions e-mail: giometti@enneenne.com Linux Device Driver giometti@linux.it Embedded Systems phone: +39 349 2432127 UNIX programming skype: rodolfo.giometti Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it -- 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/