Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761074AbXERPEl (ORCPT ); Fri, 18 May 2007 11:04:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755785AbXERPEe (ORCPT ); Fri, 18 May 2007 11:04:34 -0400 Received: from h155.mvista.com ([63.81.120.155]:31587 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755724AbXERPEe (ORCPT ); Fri, 18 May 2007 11:04:34 -0400 Message-ID: <464DC0DC.7050809@ru.mvista.com> Date: Fri, 18 May 2007 19:06:04 +0400 From: Sergei Shtylyov Organization: MontaVista Software Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.2) Gecko/20040803 X-Accept-Language: ru, en-us, en-gb MIME-Version: 1.0 To: Daniel Walker Cc: Kumar Gala , tglx@linutronix.de, mingo@elte.hu, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.21-rt2] PowerPC: decrementer clockevent driver References: <200705172142.26739.sshtylyov@ru.mvista.com> <8E44DB06-767D-4864-8D2C-6132E4D4370B@kernel.crashing.org> <464C99FF.8080404@ru.mvista.com> <135307ED-7125-4859-8594-4B5B900D92D6@kernel.crashing.org> <1179500217.20519.53.camel@imap.mvista.com> In-Reply-To: <1179500217.20519.53.camel@imap.mvista.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1020 Lines: 29 Daniel Walker wrote: >>I haven't looked at all the new clock/timer code, is there any >>utility in having support for more than one clock source? > There is if the main clocksource has some issues where it can't be used. You mean, having more than one clocksource is *useful* in this case? > On x86 there are lots of different issues with the clocks, so they have > to get switches once in a while. For instance, if the TSC changes > frequencies then it can't be used, or if the TSC stops in different > power states , it can't be used.. Yeah, and there's the rating systems for both clock sources/events. > Anything like that on PowerPC? Well, the decrementer frequency may change, at least in theory (if the bus clock changes). > Daniel WBR, Sergei - 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/