From owner-svn-src-head@FreeBSD.ORG Fri Dec 28 02:49:46 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 22E4AA2B; Fri, 28 Dec 2012 02:49:46 +0000 (UTC) (envelope-from gonzo@id.bluezbox.com) Received: from id.bluezbox.com (id.bluezbox.com [88.198.91.248]) by mx1.freebsd.org (Postfix) with ESMTP id B7E038FC08; Fri, 28 Dec 2012 02:49:45 +0000 (UTC) Received: from [88.198.91.248] (helo=[IPv6:::1]) by id.bluezbox.com with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.77 (FreeBSD)) (envelope-from ) id 1ToQ10-000Ezv-Ct; Thu, 27 Dec 2012 18:49:44 -0800 Message-ID: <50DD08C3.3080801@freebsd.org> Date: Thu, 27 Dec 2012 18:49:39 -0800 From: Oleksandr Tymoshenko User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 Subject: Re: svn commit: r244758 - head/sys/arm/broadcom/bcm2835 References: <201212280138.qBS1chFm022181@svn.freebsd.org> In-Reply-To: <201212280138.qBS1chFm022181@svn.freebsd.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: gonzo@id.bluezbox.com X-Spam-Level: - X-Spam-Report: Spam detection software, running on the system "id.bluezbox.com", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see The administrator of that system for details. Content preview: On 12/27/2012 5:38 PM, Oleksandr Tymoshenko wrote: > Author: gonzo > Date: Fri Dec 28 01:38:43 2012 > New Revision: 244758 > URL: http://svnweb.freebsd.org/changeset/base/244758 > > Log: > Fix event timer on Raspberry Pi > > - Disable interrupt when updating compare value in order to > make this operation atomical > > - Increase minimum period for event timer. Systimer on BCM2835 > is compare timer, so if minimum period is too small it might > be less then fraction of time between "read current value" and > "set compare timer" operations. It means that when timer is armed > actual counter value is more then compare value and it will take > whole cycle (~32sec for 1MHz timer) to fire interrupt. > [...] Content analysis details: (-1.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP 1.0 MISSING_HEADERS Missing To: header -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Dec 2012 02:49:46 -0000 On 12/27/2012 5:38 PM, Oleksandr Tymoshenko wrote: > Author: gonzo > Date: Fri Dec 28 01:38:43 2012 > New Revision: 244758 > URL: http://svnweb.freebsd.org/changeset/base/244758 > > Log: > Fix event timer on Raspberry Pi > > - Disable interrupt when updating compare value in order to > make this operation atomical > > - Increase minimum period for event timer. Systimer on BCM2835 > is compare timer, so if minimum period is too small it might > be less then fraction of time between "read current value" and > "set compare timer" operations. It means that when timer is armed > actual counter value is more then compare value and it will take > whole cycle (~32sec for 1MHz timer) to fire interrupt. > It's not 32, it's ~4294 seconds Spotted by: Ian Lepore