From mboxrd@z Thu Jan 1 00:00:00 1970 From: youquan_song@linux.intel.com Subject: [PATCH] ACPI: Check _PSS invalidation when BIOS report _PSS with all 0x80000000 Date: Thu, 20 Nov 2008 19:08:36 -0800 (PST) Message-ID: <3606.172.16.183.72.1227236916.squirrel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from mga07.intel.com ([143.182.124.22]:55611 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752418AbYKUDIi (ORCPT ); Thu, 20 Nov 2008 22:08:38 -0500 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Cc: venkatesh.pallipadi@intel.com, len.brown@intel.com, linux-kernel@vger.kernel.org Subject: Check _PSS invalidation when BIOS report _PSS with 0x80000000 When cpu frequencey scaling disable,some BIOS report _PSS with all 0x80000000. If kernel treat this case as valid, the kernel will boot crash when load cpufreq govenors. So in order to cover more buggy BIOSs, the patch just check _PSS core frequencey invalidtion. Signed-off-by: Youquan, Song Signed-off-by: Pallipadi, Venkatesh --- --- linux-2.6-tip-orignal/drivers/acpi/processor_perflib.c 2008-11-20 12:25:05.000000000 -0500 +++ linux-2.6-tip/drivers/acpi/processor_perflib.c 2008-11-20 12:23:57.000000000 -0500 @@ -50,6 +50,7 @@ #define ACPI_PROCESSOR_CLASS "processor" #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance" #define _COMPONENT ACPI_PROCESSOR_COMPONENT +#define ACPI_PROCESSOR_PSS_INVALID 0x80000000 ACPI_MODULE_NAME("processor_perflib"); static DEFINE_MUTEX(performance_mutex); @@ -324,6 +325,14 @@ kfree(pr->performance->states); goto end; } + + if (px->core_frequency == ACPI_PROCESSOR_PSS_INVALID) { + printk(KERN_ERR PREFIX + "P-states disabled in the BIOS\n"); + result = -EFAULT; + kfree(pr->performance->states); + goto end; + } } end: