diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index a7d0bb0880ece4c4319eac1cd4f6fbe64c358d55..d39b2774535be405eae1a5abd11dbb610ea72de0 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -162,6 +162,9 @@ int mei_hw_init(struct mei_device *dev)
 	if ((dev->host_hw_state & H_IS) == H_IS)
 		mei_reg_write(dev, H_CSR, dev->host_hw_state);
 
+	/* Doesn't change in runtime */
+	dev->hbuf_depth = (dev->host_hw_state & H_CBD) >> 24;
+
 	dev->recvd_msg = false;
 	dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
 
diff --git a/drivers/misc/mei/interface.c b/drivers/misc/mei/interface.c
index 6c0569177646e3e243735d5ea41165c6b91871d8..784a60626fa1c71375d5c8e94edc0f809dacfc0f 100644
--- a/drivers/misc/mei/interface.c
+++ b/drivers/misc/mei/interface.c
@@ -103,15 +103,14 @@ int mei_host_buffer_is_empty(struct mei_device *dev)
  */
 int mei_count_empty_write_slots(struct mei_device *dev)
 {
-	unsigned char buffer_depth, filled_slots, empty_slots;
+	unsigned char filled_slots, empty_slots;
 
 	dev->host_hw_state = mei_hcsr_read(dev);
-	buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
 	filled_slots = _host_get_filled_slots(dev);
-	empty_slots = buffer_depth - filled_slots;
+	empty_slots = dev->hbuf_depth - filled_slots;
 
 	/* check for overflow */
-	if (filled_slots > buffer_depth)
+	if (filled_slots > dev->hbuf_depth)
 		return -EOVERFLOW;
 
 	return empty_slots;
diff --git a/drivers/misc/mei/interface.h b/drivers/misc/mei/interface.h
index ddff5d16616fe80bf4bab59c21c06c0695d26f28..8723d88801499e28f36e9259c3a8bddc641a152a 100644
--- a/drivers/misc/mei/interface.h
+++ b/drivers/misc/mei/interface.h
@@ -49,6 +49,12 @@ int mei_count_empty_write_slots(struct mei_device *dev);
 
 int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *cl);
 
+static inline size_t mei_hbuf_max_data(const struct mei_device *dev)
+{
+	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
+}
+
+
 int mei_wd_send(struct mei_device *dev);
 int mei_wd_stop(struct mei_device *dev, bool preserve);
 int mei_wd_host_init(struct mei_device *dev);
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 8e4dd74b96e5c24ba7c238fce440dca6e105aa4f..4ad6a6bab5a307ab3480a1c551f651ad58751341 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -951,7 +951,7 @@ static int _mei_irq_thread_cmpl(struct mei_device *dev,	s32 *slots,
 			list_move_tail(&cb_pos->cb_list,
 				&dev->write_waiting_list.mei_cb.cb_list);
 		}
-	} else if (*slots == ((dev->host_hw_state & H_CBD) >> 24)) {
+	} else if (*slots == dev->hbuf_depth) {
 		/* buffer is still empty */
 		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 		mei_hdr->host_addr = cl->host_client_id;
@@ -1046,8 +1046,8 @@ static int _mei_irq_thread_cmpl_iamthif(struct mei_device *dev, s32 *slots,
 				&dev->write_waiting_list.mei_cb.cb_list);
 
 		}
-	} else if (*slots == ((dev->host_hw_state & H_CBD) >> 24)) {
-			/* buffer is still empty */
+	} else if (*slots == dev->hbuf_depth) {
+		/* buffer is still empty */
 		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 		mei_hdr->host_addr = cl->host_client_id;
 		mei_hdr->me_addr = cl->me_client_id;
diff --git a/drivers/misc/mei/iorw.c b/drivers/misc/mei/iorw.c
index f9cced69b65e79d388405285eb9c010cac58c6f0..50f52e21f587a229e374a9f72149186aace43777 100644
--- a/drivers/misc/mei/iorw.c
+++ b/drivers/misc/mei/iorw.c
@@ -481,12 +481,8 @@ int amthi_write(struct mei_device *dev, struct mei_cl_cb *cb)
 	if (ret && dev->mei_host_buffer_is_empty) {
 		ret = 0;
 		dev->mei_host_buffer_is_empty = false;
-		if (cb->request_buffer.size >
-			(((dev->host_hw_state & H_CBD) >> 24) * sizeof(u32))
-				-sizeof(struct mei_msg_hdr)) {
-			mei_hdr.length =
-			    (((dev->host_hw_state & H_CBD) >> 24) *
-			    sizeof(u32)) - sizeof(struct mei_msg_hdr);
+		if (cb->request_buffer.size > mei_hbuf_max_data(dev)) {
+			mei_hdr.length = mei_hbuf_max_data(dev);
 			mei_hdr.msg_complete = 0;
 		} else {
 			mei_hdr.length = cb->request_buffer.size;
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index c70333228337d28bc76d1c61510bb57b615d3a68..aaf2683ea154cb923612ff487cd497582f50fa0d 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -714,13 +714,8 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 	if (rets && dev->mei_host_buffer_is_empty) {
 		rets = 0;
 		dev->mei_host_buffer_is_empty = false;
-		if (length > ((((dev->host_hw_state & H_CBD) >> 24) *
-			sizeof(u32)) - sizeof(struct mei_msg_hdr))) {
-
-			mei_hdr.length =
-				(((dev->host_hw_state & H_CBD) >> 24) *
-				sizeof(u32)) -
-				sizeof(struct mei_msg_hdr);
+		if (length >  mei_hbuf_max_data(dev)) {
+			mei_hdr.length = mei_hbuf_max_data(dev);
 			mei_hdr.msg_complete = 0;
 		} else {
 			mei_hdr.length = length;
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 4fe653392a490054e99e61de0e8d55a45352e385..d60250d663c69579540ad68dd62c7d83c6b2f594 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -167,7 +167,10 @@ struct mei_io_list {
 	struct mei_cl_cb mei_cb;
 };
 
-/* MEI private device struct */
+/**
+ * struct mei_deive -  MEI private device struct
+ * @hbuf_depth - depth of host(write) buffer
+ */
 struct mei_device {
 	struct pci_dev *pdev;	/* pointer to pci device struct */
 	/*
@@ -205,6 +208,7 @@ struct mei_device {
 	 */
 	u32 host_hw_state;
 	u32 me_hw_state;
+	u8  hbuf_depth;
 	/*
 	 * waiting queue for receive message from FW
 	 */