Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269779AbUICTuE (ORCPT ); Fri, 3 Sep 2004 15:50:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269761AbUICTsc (ORCPT ); Fri, 3 Sep 2004 15:48:32 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.104]:63390 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S269795AbUICTi1 (ORCPT ); Fri, 3 Sep 2004 15:38:27 -0400 Subject: Re: [RFC][PATCH] new timeofday core subsystem (v.A0) From: john stultz To: george anzinger Cc: Christoph Lameter , lkml , tim@physik3.uni-rostock.de, albert@users.sourceforge.net, Ulrich.Windl@rz.uni-regensburg.de, Len Brown , linux@dominikbrodowski.de, David Mosberger , Andi Kleen , paulus@samba.org, schwidefsky@de.ibm.com, jimix@us.ibm.com, keith maanthey , greg kh , Patricia Gaughen , Chris McDermott In-Reply-To: <413820A2.80409@mvista.com> References: <1094159238.14662.318.camel@cog.beaverton.ibm.com> <1094159379.14662.322.camel@cog.beaverton.ibm.com> <1094164096.14662.345.camel@cog.beaverton.ibm.com> <1094166858.14662.367.camel@cog.beaverton.ibm.com> <1094170054.14662.391.camel@cog.beaverton.ibm.com> <1094175004.14662.440.camel@cog.beaverton.ibm.com> <413820A2.80409@mvista.com> Content-Type: text/plain Message-Id: <1094239970.14662.516.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Fri, 03 Sep 2004 12:32:51 -0700 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1299 Lines: 30 On Fri, 2004-09-03 at 00:43, George Anzinger wrote: > john stultz wrote: > > On Thu, 2004-09-02 at 17:47, Christoph Lameter wrote: > > > >>On Thu, 2 Sep 2004, john stultz wrote: > > read(): Rather then just giving the address of the register, the read > > call allows for timesource specific logic. This lets us use jiffies as a > > timesource, or in cases like the ACPI PM timesource, where the register > > must be read 3 times in order to ensure a correct value is latched, we > > can avoid having to include that logic into the generic code, so it does > > not affect systems that do not use or have that timesource. > > I am not convince that 3 reads are in fact needed. In fact, I am amost certain > that two is more than enough. In fact, it takes so long to read it that I just > use one read and a sanity check in the HRT code. Here is the code I use: [snip] I'd have to defer to Dominik (acpi-pm author) for that. But the case remains, to get a "good" value, you have to do more then just give access to the raw register. thanks -john - 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/