From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from az33egw02.freescale.net (az33egw02.freescale.net [192.88.158.103]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "az33egw02.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 0DA2EDDDFA for ; Thu, 29 Nov 2007 10:43:23 +1100 (EST) Message-ID: <474DFD15.603@freescale.com> Date: Wed, 28 Nov 2007 17:43:17 -0600 From: Scott Wood MIME-Version: 1.0 To: Alan Bennett Subject: Re: Timers on mpc8248 etc... References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Alan Bennett wrote: > I've got a routine that needs to delay for X microseconds, this is a > must. The command after schedule_timeout must has to wait for the HW > to complete a task that takes X microseconds. > > I would think that one way to do this is with a simple > schedule_timeout. But in the example below, the time that passes from > run1() to dontrun() is far less than 3.2 msecs. Infact, sometimes its > ~ 800 micros according the a analyzer looking at points triggered in > run1() and donrun(). Could this be a configuration problem with the > timer/interrupt that generates the jiffies? Are you sure the timebase frequency is set correctly in the device tree? -Scott