diff --git a/drivers/staging/mei/hw.h b/drivers/staging/mei/hw.h
index f86a213c372d..24c4c962819e 100644
--- a/drivers/staging/mei/hw.h
+++ b/drivers/staging/mei/hw.h
@@ -141,6 +141,11 @@ access to ME_CBD */
 #define HBM_MAJOR_VERSION                   1
 #define HBM_TIMEOUT                         1	/* 1 second */
 
+/* Host bus message command opcode */
+#define MEI_HBM_CMD_OP_MSK                  0x7f
+/* Host bus message command RESPONSE */
+#define MEI_HBM_CMD_RES_MSK                 0x80
+
 /*
  * MEI Bus Message Command IDs
  */
@@ -164,7 +169,7 @@ access to ME_CBD */
 #define CLIENT_DISCONNECT_REQ_CMD           0x07
 #define CLIENT_DISCONNECT_RES_CMD           0x87
 
-#define MEI_FLOW_CONTROL_CMD               0x08
+#define MEI_FLOW_CONTROL_CMD                0x08
 
 /*
  * MEI Stop Reason
@@ -213,15 +218,9 @@ struct mei_msg_hdr {
 } __packed;
 
 
-struct hbm_cmd {
-	u8 cmd:7;
-	u8 is_response:1;
-} __packed;
-
-
 struct mei_bus_message {
-	struct hbm_cmd cmd;
-	u8 command_specific_data[];
+	u8 hbm_cmd;
+	u8 data[0];
 } __packed;
 
 struct hbm_version {
@@ -230,41 +229,41 @@ struct hbm_version {
 } __packed;
 
 struct hbm_host_version_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reserved;
 	struct hbm_version host_version;
 } __packed;
 
 struct hbm_host_version_response {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 host_version_supported;
 	struct hbm_version me_max_version;
 } __packed;
 
 struct hbm_host_stop_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reason;
 	u8 reserved[2];
 } __packed;
 
 struct hbm_host_stop_response {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reserved[3];
 } __packed;
 
 struct hbm_me_stop_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reason;
 	u8 reserved[2];
 } __packed;
 
 struct hbm_host_enum_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reserved[3];
 } __packed;
 
 struct hbm_host_enum_response {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 reserved[3];
 	u8 valid_addresses[32];
 } __packed;
@@ -279,14 +278,14 @@ struct mei_client_properties {
 } __packed;
 
 struct hbm_props_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 address;
 	u8 reserved[2];
 } __packed;
 
 
 struct hbm_props_response {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 address;
 	u8 status;
 	u8 reserved[1];
@@ -294,21 +293,21 @@ struct hbm_props_response {
 } __packed;
 
 struct hbm_client_connect_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 me_addr;
 	u8 host_addr;
 	u8 reserved;
 } __packed;
 
 struct hbm_client_connect_response {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 me_addr;
 	u8 host_addr;
 	u8 status;
 } __packed;
 
 struct hbm_client_disconnect_request {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 me_addr;
 	u8 host_addr;
 	u8 reserved[1];
@@ -317,7 +316,7 @@ struct hbm_client_disconnect_request {
 #define MEI_FC_MESSAGE_RESERVED_LENGTH           5
 
 struct hbm_flow_control {
-	struct hbm_cmd cmd;
+	u8 hbm_cmd;
 	u8 me_addr;
 	u8 host_addr;
 	u8 reserved[MEI_FC_MESSAGE_RESERVED_LENGTH];
diff --git a/drivers/staging/mei/init.c b/drivers/staging/mei/init.c
index 393da4bb2022..e24b6ad3d5fb 100644
--- a/drivers/staging/mei/init.c
+++ b/drivers/staging/mei/init.c
@@ -362,7 +362,7 @@ void mei_host_start_message(struct mei_device *dev)
 	host_start_req =
 	    (struct hbm_host_version_request *) &dev->wr_msg_buf[1];
 	memset(host_start_req, 0, sizeof(struct hbm_host_version_request));
-	host_start_req->cmd.cmd = HOST_START_REQ_CMD;
+	host_start_req->hbm_cmd = HOST_START_REQ_CMD;
 	host_start_req->host_version.major_version = HBM_MAJOR_VERSION;
 	host_start_req->host_version.minor_version = HBM_MINOR_VERSION;
 	dev->recvd_msg = false;
@@ -398,7 +398,7 @@ void mei_host_enum_clients_message(struct mei_device *dev)
 
 	host_enum_req = (struct hbm_host_enum_request *) &dev->wr_msg_buf[1];
 	memset(host_enum_req, 0, sizeof(struct hbm_host_enum_request));
-	host_enum_req->cmd.cmd = HOST_ENUM_REQ_CMD;
+	host_enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
 	if (!mei_write_message(dev, mei_hdr, (unsigned char *)host_enum_req,
 				mei_hdr->length)) {
 		dev->mei_state = MEI_RESETING;
@@ -482,7 +482,7 @@ int mei_host_client_properties(struct mei_device *dev)
 
 		memset(host_cli_req, 0, sizeof(struct hbm_props_request));
 
-		host_cli_req->cmd.cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
+		host_cli_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
 		host_cli_req->address = b;
 
 		if (!mei_write_message(dev, mei_header,
diff --git a/drivers/staging/mei/interface.c b/drivers/staging/mei/interface.c
index 484be56a6594..a873be750874 100644
--- a/drivers/staging/mei/interface.c
+++ b/drivers/staging/mei/interface.c
@@ -326,7 +326,7 @@ int mei_send_flow_control(struct mei_device *dev, struct mei_cl *cl)
 	memset(mei_flow_control, 0, sizeof(*mei_flow_control));
 	mei_flow_control->host_addr = cl->host_client_id;
 	mei_flow_control->me_addr = cl->me_client_id;
-	mei_flow_control->cmd.cmd = MEI_FLOW_CONTROL_CMD;
+	mei_flow_control->hbm_cmd = MEI_FLOW_CONTROL_CMD;
 	memset(mei_flow_control->reserved, 0,
 			sizeof(mei_flow_control->reserved));
 	dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
@@ -390,7 +390,7 @@ int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
 	memset(mei_cli_disconnect, 0, sizeof(*mei_cli_disconnect));
 	mei_cli_disconnect->host_addr = cl->host_client_id;
 	mei_cli_disconnect->me_addr = cl->me_client_id;
-	mei_cli_disconnect->cmd.cmd = CLIENT_DISCONNECT_REQ_CMD;
+	mei_cli_disconnect->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
 	mei_cli_disconnect->reserved[0] = 0;
 
 	if (!mei_write_message(dev, mei_hdr,
@@ -425,7 +425,7 @@ int mei_connect(struct mei_device *dev, struct mei_cl *cl)
 	    (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
 	mei_cli_connect->host_addr = cl->host_client_id;
 	mei_cli_connect->me_addr = cl->me_client_id;
-	mei_cli_connect->cmd.cmd = CLIENT_CONNECT_REQ_CMD;
+	mei_cli_connect->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
 	mei_cli_connect->reserved = 0;
 
 	if (!mei_write_message(dev, mei_hdr,
diff --git a/drivers/staging/mei/interrupt.c b/drivers/staging/mei/interrupt.c
index 8a9044ba3573..ce14e399adab 100644
--- a/drivers/staging/mei/interrupt.c
+++ b/drivers/staging/mei/interrupt.c
@@ -597,8 +597,7 @@ static void mei_client_disconnect_request(struct mei_device *dev,
 				&dev->ext_msg_buf[1];
 			disconnect_res->host_addr = cl_pos->host_client_id;
 			disconnect_res->me_addr = cl_pos->me_client_id;
-			*(u8 *) (&disconnect_res->cmd) =
-				CLIENT_DISCONNECT_RES_CMD;
+			disconnect_res->hbm_cmd = CLIENT_DISCONNECT_RES_CMD;
 			disconnect_res->status = 0;
 			dev->extra_write_index = 2;
 			break;
@@ -634,7 +633,7 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 	mei_read_slots(dev, dev->rd_msg_buf, mei_hdr->length);
 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
 
-	switch (*(u8 *) mei_msg) {
+	switch (mei_msg->hbm_cmd) {
 	case HOST_START_RES_CMD:
 		version_res = (struct hbm_host_version_response *) mei_msg;
 		if (version_res->host_version_supported) {
@@ -665,7 +664,7 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 			memset(host_stop_req,
 					0,
 					sizeof(struct hbm_host_stop_request));
-			host_stop_req->cmd.cmd = HOST_STOP_REQ_CMD;
+			host_stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
 			host_stop_req->reason = DRIVER_STOP_REQUEST;
 			mei_write_message(dev, mei_hdr,
 					   (unsigned char *) (host_stop_req),
@@ -805,7 +804,7 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 		host_stop_req =
 			(struct hbm_host_stop_request *) &dev->ext_msg_buf[1];
 		memset(host_stop_req, 0, sizeof(struct hbm_host_stop_request));
-		host_stop_req->cmd.cmd = HOST_STOP_REQ_CMD;
+		host_stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
 		host_stop_req->reason = DRIVER_STOP_REQUEST;
 		host_stop_req->reserved[0] = 0;
 		host_stop_req->reserved[1] = 0;