ACPI: bugfix reporting of event handler status

Introduce a new flag showing whether the event has an event handler/method.

For all the GPEs and Fixed Events,
 1. ACPI_EVENT_FLAG_HANDLE is cleared, it's an "invalid" ACPI event.
 2. Both ACPI_EVENT_FLAG_HANDLE and ACPI_EVENT_FLAG_DISABLE are set,
    it's "disabled".
 3. Both ACPI_EVENT_FLAG_HANDLE and ACPI_EVENT_FLAG_ENABLE are set,
    it's "enabled".
 4. Both ACPI_EVENT_FLAG_HANDLE and ACPI_EVENT_FLAG_WAKE_ENABLE are set,
    it's "wake_enabled".

Among other things, this prevents incorrect reporting of ACPI events
as being "invalid" when it's really just (temporarily) "disabled".

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/events/evxfevnt.c b/drivers/acpi/events/evxfevnt.c
index 73bfd6b..211e93a 100644
--- a/drivers/acpi/events/evxfevnt.c
+++ b/drivers/acpi/events/evxfevnt.c
@@ -521,6 +521,9 @@
 	if (value)
 		*event_status |= ACPI_EVENT_FLAG_SET;
 
+	if (acpi_gbl_fixed_event_handlers[event].handler)
+		*event_status |= ACPI_EVENT_FLAG_HANDLE;
+
 	return_ACPI_STATUS(status);
 }
 
@@ -571,6 +574,9 @@
 
 	status = acpi_hw_get_gpe_status(gpe_event_info, event_status);
 
+	if (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)
+		*event_status |= ACPI_EVENT_FLAG_HANDLE;
+
       unlock_and_exit:
 	if (flags & ACPI_NOT_ISR) {
 		(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);