7 files changed, 24 insertions, 21 deletions

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index a7d0bb0880ec..d39b2774535b 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 6c0569177646..784a60626fa1 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 ddff5d16616f..8723d8880149 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 8e4dd74b96e5..4ad6a6bab5a3 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 f9cced69b65e..50f52e21f587 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 c70333228337..aaf2683ea154 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 4fe653392a49..d60250d663c6 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
          */