ACPI processor: reset the throttling state once it's invalid

If the BIOS hands us an invalid throttling state,
write a valid state.

http://bugzilla.kernel.org/show_bug.cgi?id=13259

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: James Ettle <theholyettlz@googlemail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/processor_throttling.c

@@ -838,6 +838,14 @@ static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 	ret = acpi_read_throttling_status(pr, &value);
 	if (ret >= 0) {
 		state = acpi_get_throttling_state(pr, value);
+		if (state == -1) {
+			ACPI_WARNING((AE_INFO,
+				"Invalid throttling state, reset\n"));
+			state = 0;
+			ret = acpi_processor_set_throttling(pr, state);
+			if (ret)
+				return ret;
+		}
 		pr->throttling.state = state;
 	}