From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754170AbYHRTwp (ORCPT ); Mon, 18 Aug 2008 15:52:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763391AbYHRTt2 (ORCPT ); Mon, 18 Aug 2008 15:49:28 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52701 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933477AbYHRTtZ (ORCPT ); Mon, 18 Aug 2008 15:49:25 -0400 Date: Mon, 18 Aug 2008 12:47:55 -0700 From: Andrew Morton To: Dominik Brodowski Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, johnstul@us.ibm.com, hirofumi@mail.parknet.co.jp, alan@lxorguk.ukuu.org.uk, arjan@infradead.org, andi@lisas.de Subject: Re: [git pull?] clocksource: ACPI pmtmr bugfixes [Was: Re: ACPI PM-Timer on K6-3 SiS5591: Houston...] Message-Id: <20080818124755.162f24d1.akpm@linux-foundation.org> In-Reply-To: <20080818193517.GA22097@isilmar.linta.de> References: <20080810101730.GA10024@rhlx01.hs-esslingen.de> <20080810162920.GA9860@comet.dominikbrodowski.net> <20080810190759.GA1879@rhlx01.hs-esslingen.de> <20080818190325.GA12581@comet.dominikbrodowski.net> <20080818121924.6b61f7af.akpm@linux-foundation.org> <20080818193517.GA22097@isilmar.linta.de> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 18 Aug 2008 21:35:17 +0200 Dominik Brodowski wrote: > Hi Andrew, > > On Mon, Aug 18, 2008 at 12:19:24PM -0700, Andrew Morton wrote: > > > git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6.git clocksource > > > > > > Dominik Brodowski (2): > > > acpi_pm.c: use proper read function also in errata mode. > > > acpi_pm.c: check for monotonicity > > > > > > drivers/clocksource/acpi_pm.c | 50 +++++++++++++++++++++++----------------- > > > 1 files changed, 29 insertions(+), 21 deletions(-) > > > > A bare git URL is somewhat user-unfriendly. > > uh, sorry about that. > > > : commit b985f0517e31c1204b5aafb94f86202948f00e16 > > : Author: Dominik Brodowski > > : Date: Sun Aug 10 21:24:21 2008 +0200 > > : > > : acpi_pm.c: use proper read function also in errata mode. > > : > > : When acpi_pm is used in errata mode (three reads instead of one), also the > > : acpi_pm init functions need to use three reads instead of just one. > > > > hm, why? Was there some observeable problem which this change improved? > > Indeed: on all affected hardware (some Intel ICH4, PIIX4 and PIIX4E chipsets) > there's about a 4.2% chance that initialization of the ACPI PMTMR fails. On > those chipsets, we need to read out the timer value at least three times to > get a correct result, for every once in a while (i.e. within a 3 ns window > every 69.8 ns) the read returns a bogus result. During normal operation we > work around this issue, but during initialization reading a bogus value may > lead to -EINVAL even though the hardware is usable. That would be useful stuff for the changelog. > > : acpi_pm.c: check for monotonicity > > : > > : Expand the check for monotonicity by doing ten tests instead of one. > > > > Why? > > Indeed: http://lkml.org/lkml/2008/8/10/77 -- quote: > "Result: catastrophic timer behaviour (a large backwards skip is possible)," > > The current check for monotonicity is way too weak. And at least on one > system out there PMTMR is unuseable, but the current check fails. yeah, that does look like 2.6.27 material. And possibly 2.6.26.x and 2.6.25.x? > > I guess this file falls under Thomas's git-hrt tree. I can queue the > > patches up and spam Thomas with them, but I'm at a bit of a loss > > regarding their priority due to the above questions. > > That would be great, thanks. Could I trouble you to resend them as plain-old-patches, with full changelogs along with your thoughts about the suitablity for 2.6.2[5678].x please? I could attempt to put all that together here, but I'd probably end up with something inappropriate. Thanks.