Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/acpi/acpi_dbg.c b/drivers/acpi/acpi_dbg.c
index f21c99e..7a265c2 100644
--- a/drivers/acpi/acpi_dbg.c
+++ b/drivers/acpi/acpi_dbg.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * ACPI AML interfacing support
  *
  * Copyright (C) 2015, Intel Corporation
  * Authors: Lv Zheng <lv.zheng@intel.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 /* #define DEBUG */
@@ -390,7 +387,7 @@
 	return size > 0 ? size : ret;
 }
 
-static int acpi_aml_thread(void *unsed)
+static int acpi_aml_thread(void *unused)
 {
 	acpi_osd_exec_callback function = NULL;
 	void *context;
@@ -614,7 +611,7 @@
 
 	if (!count)
 		return 0;
-	if (!access_ok(VERIFY_WRITE, buf, count))
+	if (!access_ok(buf, count))
 		return -EFAULT;
 
 	while (count > 0) {
@@ -684,7 +681,7 @@
 
 	if (!count)
 		return 0;
-	if (!access_ok(VERIFY_READ, buf, count))
+	if (!access_ok(buf, count))
 		return -EFAULT;
 
 	while (count > 0) {
@@ -750,48 +747,36 @@
 
 int __init acpi_aml_init(void)
 {
-	int ret = 0;
-
-	if (!acpi_debugfs_dir) {
-		ret = -ENOENT;
-		goto err_exit;
-	}
+	int ret;
 
 	/* Initialize AML IO interface */
 	mutex_init(&acpi_aml_io.lock);
 	init_waitqueue_head(&acpi_aml_io.wait);
 	acpi_aml_io.out_crc.buf = acpi_aml_io.out_buf;
 	acpi_aml_io.in_crc.buf = acpi_aml_io.in_buf;
+
 	acpi_aml_dentry = debugfs_create_file("acpidbg",
 					      S_IFREG | S_IRUGO | S_IWUSR,
 					      acpi_debugfs_dir, NULL,
 					      &acpi_aml_operations);
-	if (acpi_aml_dentry == NULL) {
-		ret = -ENODEV;
-		goto err_exit;
-	}
-	ret = acpi_register_debugger(THIS_MODULE, &acpi_aml_debugger);
-	if (ret)
-		goto err_fs;
-	acpi_aml_initialized = true;
 
-err_fs:
+	ret = acpi_register_debugger(THIS_MODULE, &acpi_aml_debugger);
 	if (ret) {
 		debugfs_remove(acpi_aml_dentry);
 		acpi_aml_dentry = NULL;
+		return ret;
 	}
-err_exit:
-	return ret;
+
+	acpi_aml_initialized = true;
+	return 0;
 }
 
 void __exit acpi_aml_exit(void)
 {
 	if (acpi_aml_initialized) {
 		acpi_unregister_debugger(&acpi_aml_debugger);
-		if (acpi_aml_dentry) {
-			debugfs_remove(acpi_aml_dentry);
-			acpi_aml_dentry = NULL;
-		}
+		debugfs_remove(acpi_aml_dentry);
+		acpi_aml_dentry = NULL;
 		acpi_aml_initialized = false;
 	}
 }