From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758736AbaELXwh (ORCPT ); Mon, 12 May 2014 19:52:37 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:65275 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758705AbaELXwf (ORCPT ); Mon, 12 May 2014 19:52:35 -0400 From: "Rafael J. Wysocki" To: "Zheng, Lv" Cc: ACPI Devel Maling List , Linux Kernel Mailing List , Oswald Buddenhagen Subject: Re: [PATCH] ACPICA: Revert "ACPICA: Add option to favor 32-bit FADT addresses." Date: Tue, 13 May 2014 02:09:20 +0200 Message-ID: <2640573.uiu9DRCeSI@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.14.0-rc7+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1AE640813FDE7649BE1B193DEA596E880255B72C@SHSMSX101.ccr.corp.intel.com> References: <38907770.bupFXhytsS@vostro.rjw.lan> <1AE640813FDE7649BE1B193DEA596E880255B3F0@SHSMSX101.ccr.corp.intel.com> <1AE640813FDE7649BE1B193DEA596E880255B72C@SHSMSX101.ccr.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, May 12, 2014 08:51:36 AM Zheng, Lv wrote: > Hi, Rafael > > I checked the bug. > > The dmesg of the kernel without the bisected commit: > [ 0.000000] ACPI BIOS Warning (bug): Incorrect checksum in table [XSDT] - 0xA0, should be 0xC9 (20140214/tbprint-218) > [ 0.000000] ACPI Warning: 32/64 FACS address mismatch in FADT - two FACS tables! (20140214/tbfadt-395) > [ 0.000000] ACPI BIOS Warning (bug): 32/64X FACS address mismatch in FADT - 0xCF661F40/0x00000000CF667E40, using 32 (20140214/tbfadt-522) > > The dmesg of the kernel with the bisected commit: > [ 0.000000] ACPI BIOS Warning (bug): Incorrect checksum in table [XSDT] - 0xA0, should be 0xC9 (20131218/tbprint-214) > [ 0.000000] ACPI BIOS Warning (bug): 32/64X FACS address mismatch in FADT: 0xCF661F40/0x00000000CF667E40, using 64-bit address (20131218/tbfadt-271) > > This is the purpose of the bisected commit. > According to the link below: > http://bugs.acpica.org/show_bug.cgi?id=885 > And Windows documentation: > http://download.microsoft.com/download/5/b/9/5b97017b-e28a-4bae-ba48-174cf47d23cd/CPA002_WH06.ppt > We believe 64-bit addresses should be used by default so that new features can be enabled according to the public knowledge of Windows Vista+ behavior. > For old Windows, it's hard for us to guess, we should wait for the reports and add quirks for them. > > Thus this commit is not wrong, it shouldn't be reverted. It is wrong, because it breaks a system that worked without it. It's *that* simple. And either you have a fix for that (which is not a quirk, because there may be more machines like that), or we have to revert it. > Though this platform is newer than vista, we still should offer a quirk mechanism > for it as a quick fix: We didn't need a quirk for it before, though. So really, I'm reverting it. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.