From owner-freebsd-questions@FreeBSD.ORG  Fri Aug  7 22:02:34 2009
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id C87AE106564A
	for <freebsd-questions@freebsd.org>;
	Fri,  7 Aug 2009 22:02:34 +0000 (UTC)
	(envelope-from cstankevitz@toyon.com)
Received: from smtp1.toyon.com (206-190-77-154.static.twtelecom.net
	[206.190.77.154])
	by mx1.freebsd.org (Postfix) with ESMTP id 9712C8FC08
	for <freebsd-questions@freebsd.org>;
	Fri,  7 Aug 2009 22:02:34 +0000 (UTC)
Received: from [172.16.1.101] (hosts253.toyon.com [65.160.147.253])
	(authenticated bits=0)
	by smtp1.toyon.com (8.13.1/8.12.11) with ESMTP id n77M7OHH008572
	for <freebsd-questions@freebsd.org>; Fri, 7 Aug 2009 15:07:24 -0700
Message-ID: <4A7CA47A.80401@toyon.com>
Date: Fri, 07 Aug 2009 15:02:34 -0700
From: Chris Stankevitz <cstankevitz@toyon.com>
User-Agent: Thunderbird 2.0.0.21 (Windows/20090302)
MIME-Version: 1.0
To: freebsd-questions@freebsd.org
References: <4A7B8FD1.9040003@toyon.com>
In-Reply-To: <4A7B8FD1.9040003@toyon.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: Strange timing when reading from the serial port
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 07 Aug 2009 22:02:35 -0000

Chris Stankevitz wrote:
> Q: What is the source of the alternating +/- 5ms bias that comes and 
> goes every few seconds?

This helps: add these lines to /boot/device.hints and reboot

hint.sio.0.flags="0x20"
hint.sio.1.flags="0x20"

Chris