Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/acpi/sbshc.c b/drivers/acpi/sbshc.c
index 7a34310..87b74e9 100644
--- a/drivers/acpi/sbshc.c
+++ b/drivers/acpi/sbshc.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * SMBus driver for ACPI Embedded Controller (v0.1)
  *
  * Copyright (c) 2007 Alexey Starikovskiy
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation version 2.
  */
 
 #include <linux/acpi.h>
@@ -196,6 +193,7 @@
 	hc->callback = NULL;
 	hc->context = NULL;
 	mutex_unlock(&hc->lock);
+	acpi_os_wait_events_complete();
 	return 0;
 }
 
@@ -292,6 +290,7 @@
 
 	hc = acpi_driver_data(device);
 	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
+	acpi_os_wait_events_complete();
 	kfree(hc);
 	device->driver_data = NULL;
 	return 0;