ACPI / ACPICA: Defer enabling of runtime GPEs (v3)

The current ACPI GPEs initialization code has a problem that it
enables some GPEs pointed to by device _PRW methods, generally
intended for signaling wakeup events (system or device wakeup).
These GPEs are then almost immediately disabled by the ACPI namespace
scanning code with the help of acpi_gpe_can_wake(), but it would be
better not to enable them at all until really necessary.

Modify the initialization of GPEs so that the ones that have
associated _Lxx or _Exx methods and are not pointed to by any _PRW
methods will be enabled after the namespace scan is complete.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/evxfevnt.c

@@ -379,21 +379,12 @@ acpi_status acpi_gpe_can_wake(acpi_handle gpe_device, u32 gpe_number)
 	/* Ensure that we have a valid GPE number */
 
 	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
-	if (!gpe_event_info) {
+	if (gpe_event_info) {
+		gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
+	} else {
 		status = AE_BAD_PARAMETER;
-		goto unlock_and_exit;
 	}
 
-	if (gpe_event_info->flags & ACPI_GPE_CAN_WAKE) {
-		goto unlock_and_exit;
-	}
-
-	gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
-	if (gpe_event_info->flags & ACPI_GPE_DISPATCH_METHOD) {
-		(void)acpi_raw_disable_gpe(gpe_event_info);
-	}
-
-unlock_and_exit:
 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 	return_ACPI_STATUS(status);
 }
@@ -651,7 +642,7 @@ acpi_install_gpe_block(acpi_handle gpe_device,
 		       struct acpi_generic_address *gpe_block_address,
 		       u32 register_count, u32 interrupt_number)
 {
-	acpi_status status;
+	acpi_status status = AE_OK;
 	union acpi_operand_object *obj_desc;
 	struct acpi_namespace_node *node;
 	struct acpi_gpe_block_info *gpe_block;
@@ -715,10 +706,6 @@ acpi_install_gpe_block(acpi_handle gpe_device,
 
 	obj_desc->device.gpe_block = gpe_block;
 
-	/* Enable the runtime GPEs in the new block */
-
-	status = acpi_ev_initialize_gpe_block(node, gpe_block);
-
       unlock_and_exit:
 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 	return_ACPI_STATUS(status);
@@ -924,3 +911,43 @@ acpi_status acpi_enable_all_runtime_gpes(void)
 
 	return_ACPI_STATUS(status);
 }
+
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_update_gpes
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Enable all GPEs that have associated _Lxx or _Exx methods and
+ *              are not pointed to by any device _PRW methods indicating that
+ *              these GPEs are generally intended for system or device wakeup
+ *              (such GPEs have to be enabled directly when the devices whose
+ *              _PRW methods point to them are set up for wakeup signaling).
+ *
+ ******************************************************************************/
+
+acpi_status acpi_update_gpes(void)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_update_gpes);
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	} else if (acpi_all_gpes_initialized) {
+		goto unlock;
+	}
+
+	status = acpi_ev_walk_gpe_list(acpi_ev_initialize_gpe_block, NULL);
+	if (ACPI_SUCCESS(status)) {
+		acpi_all_gpes_initialized = TRUE;
+	}
+
+unlock:
+	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
+
+	return_ACPI_STATUS(status);
+}