From mboxrd@z Thu Jan 1 00:00:00 1970 From: yakui_zhao Subject: [PATCH]: ACPI: Sort the ACPI P-state table in descending order by cpufre Date: Fri, 26 Jun 2009 10:06:41 +0800 Message-ID: <1245982001.7266.120.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:39746 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752306AbZFZCFc (ORCPT ); Thu, 25 Jun 2009 22:05:32 -0400 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: lenb@kernel.org Cc: linux-acpi@vger.kernel.org, ming.m.lin@intel.com From: Zhao Yakui According to ACPI spec the the _PSS object indicates to OSPM the supported processor performance states. And they should be sorted in descending order by cpufreq. But unfortunately on some boxes the cpufreq in _PSS object is sorted in ascending order, which causes that cpufreq driver can't work well. Sort the ACPI P-state table in descending order by cpufreq. http://bugzilla.kernel.org/show_bug.cgi?id=13529 Signed-off-by: Zhao Yakui tested-by: Mukik182 cc: Ling Ming --- drivers/acpi/processor_perflib.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) Index: linux-2.6/drivers/acpi/processor_perflib.c =================================================================== --- linux-2.6.orig/drivers/acpi/processor_perflib.c 2009-06-25 09:00:40.000000000 +0800 +++ linux-2.6/drivers/acpi/processor_perflib.c 2009-06-26 09:59:54.000000000 +0800 @@ -38,6 +38,7 @@ #include #include #include +#include #define ACPI_PROCESSOR_CLASS "processor" #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance" @@ -246,6 +247,25 @@ return result; } +static int pss_cmp_func(const void *a, const void *b) +{ + struct acpi_processor_px *pxa, *pxb; + acpi_integer acpi_value; + + pxa = (struct acpi_processor_px *)a; + pxb = (struct acpi_processor_px *)b; + + acpi_value = pxb->core_frequency - pxa->core_frequency; + return (int) acpi_value; +} +static void pss_swap_func(void *a, void *b, int size) +{ + struct acpi_processor_px temp_px; + + memcpy((void *)&temp_px, a, size); + memcpy(a, b, size); + memcpy(b, (void *)&temp_px, size); +} static int acpi_processor_get_performance_states(struct acpi_processor *pr) { int result = 0; @@ -323,7 +343,10 @@ goto end; } } - + sort((void *)(pr->performance->states), pr->performance->state_count, + sizeof(struct acpi_processor_px), + pss_cmp_func, + pss_swap_func); end: kfree(buffer.pointer);