From: Zhao Yakui <yakui.zhao@xxxxxxxxx> 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 <yakui.zhao@xxxxxxxxx> tested-by: Mukik182 <mukik182@xxxxxxxxx> cc: Ling Ming <ming.m.lin@xxxxxxxxx> --- 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 <acpi/acpi_bus.h> #include <acpi/acpi_drivers.h> #include <acpi/processor.h> +#include <linux/sort.h> #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); -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
