diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c b/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c
index c2dd2de6bc20..db278ff4cc4d 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c
@@ -13,8 +13,8 @@
 #define SETBIOSDEFAULTS_METHOD_ID					0x03
 #define SETATTRIBUTE_METHOD_ID						0x04
 
-static int call_biosattributes_interface(struct wmi_device *wdev, char *in_args, size_t size,
-					int method_id)
+static int call_biosattributes_interface(struct wmi_device *wdev, u8 *in_args,
+					 size_t size, int method_id)
 {
 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 	struct acpi_buffer input;
@@ -51,7 +51,7 @@ int set_attribute(const char *a_name, const char *a_value)
 {
 	size_t security_area_size, buffer_size;
 	size_t a_name_size, a_value_size;
-	char *buffer = NULL, *start;
+	u8 *buffer = NULL, *start;
 	int ret;
 
 	mutex_lock(&wmi_priv.mutex);
@@ -109,7 +109,7 @@ int set_bios_defaults(u8 deftype)
 {
 	size_t security_area_size, buffer_size;
 	size_t integer_area_size = sizeof(u8);
-	char *buffer = NULL;
+	u8 *buffer = NULL;
 	u8 *defaultType;
 	int ret;
 
diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
index 5278a93fdaf7..3bddedad5eba 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
@@ -190,8 +190,8 @@ int init_bios_attr_set_interface(void);
 int map_wmi_error(int error_code);
 size_t calculate_string_buffer(const char *str);
 size_t calculate_security_buffer(const char *authentication);
-void populate_security_buffer(char *buffer, const char *authentication);
-ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str);
+void populate_security_buffer(u8 *buffer, const char *authentication);
+ssize_t populate_string_buffer(u8 *buffer, size_t buffer_len, const char *str);
 int set_new_password(const char *password_type, const char *new);
 int init_bios_attr_pass_interface(void);
 void exit_bios_attr_pass_interface(void);
diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c b/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
index e586f7957946..026c134b3f97 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
@@ -8,7 +8,7 @@
 #include <linux/wmi.h>
 #include "dell-wmi-sysman.h"
 
-static int call_password_interface(struct wmi_device *wdev, char *in_args, size_t size)
+static int call_password_interface(struct wmi_device *wdev, u8 *in_args, size_t size)
 {
 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 	struct acpi_buffer input;
@@ -42,7 +42,7 @@ int set_new_password(const char *password_type, const char *new)
 {
 	size_t password_type_size, current_password_size, new_size;
 	size_t security_area_size, buffer_size;
-	char *buffer = NULL, *start;
+	u8 *buffer = NULL, *start;
 	char *current_password;
 	int ret;
 
diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
index 51d25fdc1389..ab46a023cc34 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
@@ -36,7 +36,7 @@ static int reset_option = -1;
  * @buffer_len: length of the destination buffer
  * @str: the string to insert into buffer
  */
-ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str)
+ssize_t populate_string_buffer(u8 *buffer, size_t buffer_len, const char *str)
 {
 	u16 *length = (u16 *)buffer;
 	u16 *target = length + 1;
@@ -87,10 +87,10 @@ size_t calculate_security_buffer(const char *authentication)
  *
  * Currently only supported type is PLAIN TEXT
  */
-void populate_security_buffer(char *buffer, const char *authentication)
+void populate_security_buffer(u8 *buffer, const char *authentication)
 {
 	size_t seclen = strlen(authentication);
-	char *auth = buffer + sizeof(u32) * 2;
+	u8 *auth = buffer + sizeof(u32) * 2;
 	u32 *sectype = (u32 *) buffer;
 	u32 *seclenp = sectype + 1;