From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754442Ab1LLWHl (ORCPT ); Mon, 12 Dec 2011 17:07:41 -0500 Received: from tru75-7-88-161-131-83.fbx.proxad.net ([88.161.131.83]:56115 "EHLO next.fork.zz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754244Ab1LLWHj (ORCPT ); Mon, 12 Dec 2011 17:07:39 -0500 X-Greylist: delayed 411 seconds by postgrey-1.27 at vger.kernel.org; Mon, 12 Dec 2011 17:07:38 EST Message-ID: <4EE6792A.8070901@free.fr> Date: Mon, 12 Dec 2011 22:59:06 +0100 From: Wallak User-Agent: Mozilla/5.0 (X11; Linux i686; rv:8.0.1) Gecko/20111122 Firefox/8.0.1 SeaMonkey/2.5 MIME-Version: 1.0 To: Lin Ming CC: Bjorn Helgaas , linux-kernel@vger.kernel.org, linux-acpi , lenb Subject: Re: ACPI "_PDC" - acpi_processor_set_pdc()- execution regression - Linux-3.x References: <1323297487.4edfeacfc49ff@imp.free.fr> <1323657511.17515.11.camel@minggr> In-Reply-To: <1323657511.17515.11.camel@minggr> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lin Ming, This last patch, modifying the behavior of acpi_get_cpuid(), works fine on my non SMP enabled kernel. The test was done on a Dell X300, acpi_processor_set_pdc() was properly called, without the changes done by my previous patch. Best Regards, Wallak. Lin Ming wrote: > On Mon, 2011-12-12 at 10:26 +0800, Lin Ming wrote: >> ---------- Forwarded message ---------- >> From: >> Date: Thu, Dec 8, 2011 at 6:38 AM >> Subject: ACPI "_PDC" - acpi_processor_set_pdc()- execution regression >> - Linux-3.x >> To: linux-kernel@vger.kernel.org >> >> >> We have a regression on the ACPI stack of the last linux kernel line 3.x (3.1.4, >> 3.2-rc4...). The ACPI "_PDC" chunk is not executed on some computers (e.g. Dell >> X300; the function acpi_processor_set_pdc() is not called). This issue yield to >> an uninitialized state of some ACPI variables. >> >> A patch is available below. This patch come back to the previous linux behavior, >> and works fine. >> >> Best Regards, >> Wallak. >> >> --- linux-3.1.4-mdf/drivers/acpi/processor_core.c.orig 2011-12-07 >> 23:12:57.000000000 +0100 >> +++ linux-3.1.4-mdf/drivers/acpi/processor_core.c 2011-12-07 >> 23:13:39.000000000 +0100 >> @@ -223,8 +223,8 @@ >> type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; >> cpuid = acpi_get_cpuid(handle, type, acpi_id); >> >> - if (cpuid == -1) >> - return false; >> + if ((cpuid == -1)&& (num_possible_cpus()> 1)) > Hi Wallak, > > BIOS may define multiple CPU handles even for UP > processor(see below). > > processor_physically_present(acpi_handle handle) will be called for each > CPU handles. > > We should only return valid value for CPU0 on UP processor. > With your patch, processor_physically_present will return true for all > CPU handles(CPU0, CPU1, CPU2, CPU3). This is not we want. > > I think below is the correct fix. > Could you help to test it? > > Thanks. > > > From 5c6de7311ced7a1febf85fdcc08b6116bcfe8138 Mon Sep 17 00:00:00 2001 > From: Lin Ming > Date: Mon, 12 Dec 2011 10:04:53 +0800 > Subject: [PATCH] ACPI: processor: fix acpi_get_cpuid for UP processor > > For UP processor, it is likely that no _MAT method or MADT table defined. > So currently acpi_get_cpuid(...) always return -1 for UP processor. > This is wrong. It should return valid value for CPU0. > > In the other hand, BIOS may define multiple CPU handles even for UP > processor, for example > > Scope (_PR) > { > Processor (CPU0, 0x00, 0x00000410, 0x06) {} > Processor (CPU1, 0x01, 0x00000410, 0x06) {} > Processor (CPU2, 0x02, 0x00000410, 0x06) {} > Processor (CPU3, 0x03, 0x00000410, 0x06) {} > } > > We should only return valid value for CPU0's acpi handle. > And return invalid value for others. > > http://marc.info/?t=132329819900003&r=1&w=2 > > Reported-by: wallak@free.fr > Signed-off-by: Lin Ming > --- > drivers/acpi/processor_core.c | 26 ++++++++++++++++++++++++-- > 1 files changed, 24 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c > index 3a0428e..3372900 100644 > --- a/drivers/acpi/processor_core.c > +++ b/drivers/acpi/processor_core.c > @@ -173,8 +173,30 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id) > apic_id = map_mat_entry(handle, type, acpi_id); > if (apic_id == -1) > apic_id = map_madt_entry(type, acpi_id); > - if (apic_id == -1) > - return apic_id; > + if (apic_id == -1) { > + /* > + * On UP processor, there is no _MAT or MADT table. > + * So above apic_id is always set to -1. > + * > + * BIOS may define multiple CPU handles even for UP processor. > + * For example, > + * > + * Scope (_PR) > + * { > + * Processor (CPU0, 0x00, 0x00000410, 0x06) {} > + * Processor (CPU1, 0x01, 0x00000410, 0x06) {} > + * Processor (CPU2, 0x02, 0x00000410, 0x06) {} > + * Processor (CPU3, 0x03, 0x00000410, 0x06) {} > + * } > + * > + * Ignores apic_id and always return 0 for CPU0's handle. > + * Return -1 for other CPU's handle. > + */ > + if (acpi_id == 0) > + return acpi_id; > + else > + return apic_id; > + } > > #ifdef CONFIG_SMP > for_each_possible_cpu(i) {