ACPI / ACPICA: Implicit notify for multiple devices

Commit bba63a2 (ACPICA: Implicit notify support) introduced a
mechanism that causes a notify request of type
ACPI_NOTIFY_DEVICE_WAKE to be queued automatically by
acpi_ev_asynch_execute_gpe_method() for the device whose _PRW points
to the GPE being handled if that GPE is not associated with an
_Lxx/_Exx method.  However, it turns out that on some systems there
are multiple devices with _PRW pointing to the same GPE without
_Lxx/_Exx and the mechanism introduced by commit bba63a2 needs to be
extended so that "implicit" notify requests of type
ACPI_NOTIFY_DEVICE_WAKE can be queued automatically for all those
devices at the same time.

Reported-and-tested-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index 14988a8..f472521 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -457,6 +457,7 @@
 	acpi_status status;
 	struct acpi_gpe_event_info *local_gpe_event_info;
 	struct acpi_evaluate_info *info;
+	struct acpi_gpe_notify_object *notify_object;
 
 	ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 
@@ -508,10 +509,18 @@
 		 * from this thread -- because handlers may in turn run other
 		 * control methods.
 		 */
-		status =
-		    acpi_ev_queue_notify_request(local_gpe_event_info->dispatch.
-						 device_node,
-						 ACPI_NOTIFY_DEVICE_WAKE);
+		status = acpi_ev_queue_notify_request(
+				local_gpe_event_info->dispatch.device.node,
+				ACPI_NOTIFY_DEVICE_WAKE);
+
+		notify_object = local_gpe_event_info->dispatch.device.next;
+		while (ACPI_SUCCESS(status) && notify_object) {
+			status = acpi_ev_queue_notify_request(
+					notify_object->node,
+					ACPI_NOTIFY_DEVICE_WAKE);
+			notify_object = notify_object->next;
+		}
+
 		break;
 
 	case ACPI_GPE_DISPATCH_METHOD: