From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fed1rmmtao03.cox.net (fed1rmmtao03.cox.net [68.230.241.36]) by ozlabs.org (Postfix) with ESMTP id 0477D680B8 for ; Fri, 12 Aug 2005 05:43:09 +1000 (EST) Date: Thu, 11 Aug 2005 12:43:07 -0700 From: Tom Rini To: Matt Porter , Leigh Brown Message-ID: <20050811194307.GW3187@smtp.west.cox.net> References: <20050810093735.B22586@cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20050810093735.B22586@cox.net> Cc: linuxppc-dev@ozlabs.org Subject: Re: [PATCH] Use todc on Mot PReP platforms List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Aug 10, 2005 at 09:37:35AM -0700, Matt Porter wrote: > This restores behavior from 2.4 where PReP platforms identified > as Motorola would calibrate the decrementer using the RTC. On > real Motorola PReP hardware this isn't needed. However, in order > to boot a stock 2.6 PReP kernel on qemu (which emulates a Motorola > PReP system) it is necessary to allow it to calibrate the decrementer > using an emulated RTC. If the decrementer rate is read from > residual data then timing is screwed since a qemu PReP system typically > runs much faster than the original hardware. > > If anybody has objections to this as the default, let me know. It > still works (as did 2.4) on a couple of my Mot PReP boxes and doesn't > affect the IBM PReP paths. My goal with this is to be able to run > a stock 2.6 defconfig PReP build on qemu. So, I like this, and not just because I'm playing with qemu as well. Leigh, can you run this on any 'interesting' PReP you've got that might tickle a bug here? Thanks. -- Tom Rini http://gate.crashing.org/~trini/