From d81c45e1c9369855901420f79114852eba2ea16a Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Fri, 16 Oct 2009 09:20:41 +0800 Subject: ACPI: Notify the _PPC evaluation status to the platform According to the ACPI spec(section 8.4.4.3) OSPM should convey the _PPC evaluations status to the platform if there exists the _OST object. The _OST contains two arguments: The first is the PERFORMANCE notificatin event. The second is the status of _PPC object. OSPM will convey the _PPC evaluation status to the platform. Of course when the module parameter of "ignore_ppc" is added, OSPM won't evaluate the _PPC object. But it will call the _OST object. At the same time the _OST object will be evaluated only when the PERFORMANCE notification event is received. Signed-off-by: Zhao Yakui Signed-off-by: Len Brown --- drivers/acpi/processor_perflib.c | 50 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 47 insertions(+), 3 deletions(-) (limited to 'drivers/acpi/processor_perflib.c') diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 8ba0ed0b9ddb..fc1f49bbbeef 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -152,15 +152,59 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr) return 0; } -int acpi_processor_ppc_has_changed(struct acpi_processor *pr) +#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 +/* + * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status + * @handle: ACPI processor handle + * @status: the status code of _PPC evaluation + * 0: success. OSPM is now using the performance state specificed. + * 1: failure. OSPM has not changed the number of P-states in use + */ +static void acpi_processor_ppc_ost(acpi_handle handle, int status) +{ + union acpi_object params[2] = { + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + }; + struct acpi_object_list arg_list = {2, params}; + acpi_handle temp; + + params[0].integer.value = ACPI_PROCESSOR_NOTIFY_PERFORMANCE; + params[1].integer.value = status; + + /* when there is no _OST , skip it */ + if (ACPI_FAILURE(acpi_get_handle(handle, "_OST", &temp))) + return; + + acpi_evaluate_object(handle, "_OST", &arg_list, NULL); + return; +} + +int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag) { int ret; - if (ignore_ppc) + if (ignore_ppc) { + /* + * Only when it is notification event, the _OST object + * will be evaluated. Otherwise it is skipped. + */ + if (event_flag) + acpi_processor_ppc_ost(pr->handle, 1); return 0; + } ret = acpi_processor_get_platform_limit(pr); - + /* + * Only when it is notification event, the _OST object + * will be evaluated. Otherwise it is skipped. + */ + if (event_flag) { + if (ret < 0) + acpi_processor_ppc_ost(pr->handle, 1); + else + acpi_processor_ppc_ost(pr->handle, 0); + } if (ret < 0) return (ret); else -- cgit v1.2.1