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 <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 8ba0ed0..fc1f49bb 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -152,15 +152,59 @@
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