1 files changed, 298 insertions, 306 deletions

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 3535b2676c9..4e3cba6da3f 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -15,6 +15,7 @@
  */
 
 
+#include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/kthread.h>
 #include <linux/interrupt.h>
@@ -25,108 +26,129 @@
 
 #include "mei_dev.h"
 #include "hbm.h"
-#include "hw-me.h"
 #include "client.h"
 
 
 /**
- * mei_complete_handler - processes completed operation.
+ * mei_irq_compl_handler - dispatch complete handlers
+ *	for the completed callbacks
  *
- * @cl: private data of the file object.
- * @cb_pos: callback block.
+ * @dev - mei device
+ * @compl_list - list of completed cbs
  */
-void mei_irq_complete_handler(struct mei_cl *cl, struct mei_cl_cb *cb_pos)
+void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *compl_list)
 {
-	if (cb_pos->fop_type == MEI_FOP_WRITE) {
-		mei_io_cb_free(cb_pos);
-		cb_pos = NULL;
-		cl->writing_state = MEI_WRITE_COMPLETE;
-		if (waitqueue_active(&cl->tx_wait))
-			wake_up_interruptible(&cl->tx_wait);
-
-	} else if (cb_pos->fop_type == MEI_FOP_READ &&
-			MEI_READING == cl->reading_state) {
-		cl->reading_state = MEI_READ_COMPLETE;
-		if (waitqueue_active(&cl->rx_wait))
-			wake_up_interruptible(&cl->rx_wait);
+	struct mei_cl_cb *cb, *next;
+	struct mei_cl *cl;
+
+	list_for_each_entry_safe(cb, next, &compl_list->list, list) {
+		cl = cb->cl;
+		list_del(&cb->list);
+		if (!cl)
+			continue;
 
+		dev_dbg(&dev->pdev->dev, "completing call back.\n");
+		if (cl == &dev->iamthif_cl)
+			mei_amthif_complete(dev, cb);
+		else
+			mei_cl_complete(cl, cb);
 	}
 }
+EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
 
 /**
- * _mei_irq_thread_state_ok - checks if mei header matches file private data
+ * mei_cl_hbm_equal - check if hbm is addressed to the client
  *
- * @cl: private data of the file object
+ * @cl: host client
  * @mei_hdr: header of mei client message
  *
- * returns !=0 if matches, 0 if no match.
+ * returns true if matches, false otherwise
+ */
+static inline int mei_cl_hbm_equal(struct mei_cl *cl,
+			struct mei_msg_hdr *mei_hdr)
+{
+	return cl->host_client_id == mei_hdr->host_addr &&
+		cl->me_client_id == mei_hdr->me_addr;
+}
+/**
+ * mei_cl_is_reading - checks if the client
+		is the one to read this message
+ *
+ * @cl: mei client
+ * @mei_hdr: header of mei message
+ *
+ * returns true on match and false otherwise
  */
-static int _mei_irq_thread_state_ok(struct mei_cl *cl,
-				struct mei_msg_hdr *mei_hdr)
+static bool mei_cl_is_reading(struct mei_cl *cl, struct mei_msg_hdr *mei_hdr)
 {
-	return (cl->host_client_id == mei_hdr->host_addr &&
-		cl->me_client_id == mei_hdr->me_addr &&
+	return mei_cl_hbm_equal(cl, mei_hdr) &&
 		cl->state == MEI_FILE_CONNECTED &&
-		MEI_READ_COMPLETE != cl->reading_state);
+		cl->reading_state != MEI_READ_COMPLETE;
 }
 
 /**
- * mei_irq_thread_read_client_message - bottom half read routine after ISR to
- * handle the read mei client message data processing.
+ * mei_irq_read_client_message - process client message
  *
- * @complete_list: An instance of our list structure
  * @dev: the device structure
  * @mei_hdr: header of mei client message
+ * @complete_list: An instance of our list structure
  *
  * returns 0 on success, <0 on failure.
  */
-static int mei_irq_thread_read_client_message(struct mei_cl_cb *complete_list,
-		struct mei_device *dev,
-		struct mei_msg_hdr *mei_hdr)
+static int mei_cl_irq_read_msg(struct mei_device *dev,
+			       struct mei_msg_hdr *mei_hdr,
+			       struct mei_cl_cb *complete_list)
 {
 	struct mei_cl *cl;
-	struct mei_cl_cb *cb_pos = NULL, *cb_next = NULL;
+	struct mei_cl_cb *cb, *next;
 	unsigned char *buffer = NULL;
 
-	dev_dbg(&dev->pdev->dev, "start client msg\n");
-	if (list_empty(&dev->read_list.list))
-		goto quit;
+	list_for_each_entry_safe(cb, next, &dev->read_list.list, list) {
+		cl = cb->cl;
+		if (!cl || !mei_cl_is_reading(cl, mei_hdr))
+			continue;
+
+		cl->reading_state = MEI_READING;
 
-	list_for_each_entry_safe(cb_pos, cb_next, &dev->read_list.list, list) {
-		cl = cb_pos->cl;
-		if (cl && _mei_irq_thread_state_ok(cl, mei_hdr)) {
-			cl->reading_state = MEI_READING;
-			buffer = cb_pos->response_buffer.data + cb_pos->buf_idx;
+		if (cb->response_buffer.size == 0 ||
+		    cb->response_buffer.data == NULL) {
+			cl_err(dev, cl, "response buffer is not allocated.\n");
+			list_del(&cb->list);
+			return -ENOMEM;
+		}
 
-			if (cb_pos->response_buffer.size <
-					mei_hdr->length + cb_pos->buf_idx) {
-				dev_dbg(&dev->pdev->dev, "message overflow.\n");
-				list_del(&cb_pos->list);
+		if (cb->response_buffer.size < mei_hdr->length + cb->buf_idx) {
+			cl_dbg(dev, cl, "message overflow. size %d len %d idx %ld\n",
+				cb->response_buffer.size,
+				mei_hdr->length, cb->buf_idx);
+			buffer = krealloc(cb->response_buffer.data,
+					  mei_hdr->length + cb->buf_idx,
+					  GFP_KERNEL);
+
+			if (!buffer) {
+				cl_err(dev, cl, "allocation failed.\n");
+				list_del(&cb->list);
 				return -ENOMEM;
 			}
-			if (buffer)
-				mei_read_slots(dev, buffer, mei_hdr->length);
-
-			cb_pos->buf_idx += mei_hdr->length;
-			if (mei_hdr->msg_complete) {
-				cl->status = 0;
-				list_del(&cb_pos->list);
-				dev_dbg(&dev->pdev->dev,
-					"completed read H cl = %d, ME cl = %d, length = %lu\n",
-					cl->host_client_id,
-					cl->me_client_id,
-					cb_pos->buf_idx);
-
-				list_add_tail(&cb_pos->list,
-						&complete_list->list);
-			}
-
-			break;
+			cb->response_buffer.data = buffer;
+			cb->response_buffer.size =
+				mei_hdr->length + cb->buf_idx;
 		}
 
+		buffer = cb->response_buffer.data + cb->buf_idx;
+		mei_read_slots(dev, buffer, mei_hdr->length);
+
+		cb->buf_idx += mei_hdr->length;
+		if (mei_hdr->msg_complete) {
+			cl->status = 0;
+			list_del(&cb->list);
+			cl_dbg(dev, cl, "completed read length = %lu\n",
+				cb->buf_idx);
+			list_add_tail(&cb->list, &complete_list->list);
+		}
+		break;
 	}
 
-quit:
 	dev_dbg(&dev->pdev->dev, "message read\n");
 	if (!buffer) {
 		mei_read_slots(dev, dev->rd_msg_buf, mei_hdr->length);
@@ -138,179 +160,162 @@ quit:
 }
 
 /**
- * _mei_irq_thread_close - processes close related operation.
+ * mei_cl_irq_disconnect_rsp - send disconnection response message
  *
- * @dev: the device structure.
- * @slots: free slots.
- * @cb_pos: callback block.
- * @cl: private data of the file object.
+ * @cl: client
+ * @cb: callback block.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise, error.
  */
-static int _mei_irq_thread_close(struct mei_device *dev, s32 *slots,
-				struct mei_cl_cb *cb_pos,
-				struct mei_cl *cl,
-				struct mei_cl_cb *cmpl_list)
+static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
+				     struct mei_cl_cb *cmpl_list)
 {
-	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
-			sizeof(struct hbm_client_connect_request)))
-		return -EBADMSG;
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
 
-	*slots -= mei_data2slots(sizeof(struct hbm_client_connect_request));
+	slots = mei_hbuf_empty_slots(dev);
+	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
 
-	if (mei_hbm_cl_disconnect_req(dev, cl)) {
-		cl->status = 0;
-		cb_pos->buf_idx = 0;
-		list_move_tail(&cb_pos->list, &cmpl_list->list);
+	if (slots < msg_slots)
 		return -EMSGSIZE;
-	} else {
-		cl->state = MEI_FILE_DISCONNECTING;
-		cl->status = 0;
-		cb_pos->buf_idx = 0;
-		list_move_tail(&cb_pos->list, &dev->ctrl_rd_list.list);
-		cl->timer_count = MEI_CONNECT_TIMEOUT;
-	}
 
-	return 0;
+	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
+
+	cl->state = MEI_FILE_DISCONNECTED;
+	cl->status = 0;
+	list_del(&cb->list);
+	mei_io_cb_free(cb);
+
+	return ret;
 }
 
 
+
 /**
- * _mei_hb_read - processes read related operation.
+ * mei_cl_irq_close - processes close related operation from
+ *	interrupt thread context - send disconnect request
  *
- * @dev: the device structure.
- * @slots: free slots.
- * @cb_pos: callback block.
- * @cl: private data of the file object.
+ * @cl: client
+ * @cb: callback block.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise, error.
  */
-static int _mei_irq_thread_read(struct mei_device *dev,	s32 *slots,
-			struct mei_cl_cb *cb_pos,
-			struct mei_cl *cl,
-			struct mei_cl_cb *cmpl_list)
+static int mei_cl_irq_close(struct mei_cl *cl, struct mei_cl_cb *cb,
+			    struct mei_cl_cb *cmpl_list)
 {
-	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
-			sizeof(struct hbm_flow_control))) {
-		/* return the cancel routine */
-		list_del(&cb_pos->list);
-		return -EBADMSG;
-	}
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
 
-	*slots -= mei_data2slots(sizeof(struct hbm_flow_control));
+	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
+	slots = mei_hbuf_empty_slots(dev);
 
-	if (mei_hbm_cl_flow_control_req(dev, cl)) {
-		cl->status = -ENODEV;
-		cb_pos->buf_idx = 0;
-		list_move_tail(&cb_pos->list, &cmpl_list->list);
-		return -ENODEV;
+	if (slots < msg_slots)
+		return -EMSGSIZE;
+
+	if (mei_hbm_cl_disconnect_req(dev, cl)) {
+		cl->status = 0;
+		cb->buf_idx = 0;
+		list_move_tail(&cb->list, &cmpl_list->list);
+		return -EIO;
 	}
-	list_move_tail(&cb_pos->list, &dev->read_list.list);
+
+	cl->state = MEI_FILE_DISCONNECTING;
+	cl->status = 0;
+	cb->buf_idx = 0;
+	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
+	cl->timer_count = MEI_CONNECT_TIMEOUT;
 
 	return 0;
 }
 
 
 /**
- * _mei_irq_thread_ioctl - processes ioctl related operation.
+ * mei_cl_irq_close - processes client read related operation from the
+ *	interrupt thread context - request for flow control credits
  *
- * @dev: the device structure.
- * @slots: free slots.
- * @cb_pos: callback block.
- * @cl: private data of the file object.
+ * @cl: client
+ * @cb: callback block.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise, error.
  */
-static int _mei_irq_thread_ioctl(struct mei_device *dev, s32 *slots,
-			struct mei_cl_cb *cb_pos,
-			struct mei_cl *cl,
-			struct mei_cl_cb *cmpl_list)
+static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
+			   struct mei_cl_cb *cmpl_list)
 {
-	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
-			sizeof(struct hbm_client_connect_request))) {
-		/* return the cancel routine */
-		list_del(&cb_pos->list);
-		return -EBADMSG;
-	}
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
 
-	cl->state = MEI_FILE_CONNECTING;
-	*slots -= mei_data2slots(sizeof(struct hbm_client_connect_request));
-	if (mei_hbm_cl_connect_req(dev, cl)) {
-		cl->status = -ENODEV;
-		cb_pos->buf_idx = 0;
-		list_del(&cb_pos->list);
-		return -ENODEV;
-	} else {
-		list_move_tail(&cb_pos->list, &dev->ctrl_rd_list.list);
-		cl->timer_count = MEI_CONNECT_TIMEOUT;
+	msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
+	slots = mei_hbuf_empty_slots(dev);
+
+	if (slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_hbm_cl_flow_control_req(dev, cl);
+	if (ret) {
+		cl->status = ret;
+		cb->buf_idx = 0;
+		list_move_tail(&cb->list, &cmpl_list->list);
+		return ret;
 	}
+
+	list_move_tail(&cb->list, &dev->read_list.list);
+
 	return 0;
 }
 
+
 /**
- * mei_irq_thread_write_complete - write messages to device.
+ * mei_cl_irq_connect - send connect request in irq_thread context
  *
- * @dev: the device structure.
- * @slots: free slots.
+ * @cl: client
  * @cb: callback block.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise, error.
  */
-static int mei_irq_thread_write_complete(struct mei_device *dev, s32 *slots,
-			struct mei_cl_cb *cb, struct mei_cl_cb *cmpl_list)
+static int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
+			      struct mei_cl_cb *cmpl_list)
 {
-	struct mei_msg_hdr mei_hdr;
-	struct mei_cl *cl = cb->cl;
-	size_t len = cb->request_buffer.size - cb->buf_idx;
-	size_t msg_slots = mei_data2slots(len);
-
-	mei_hdr.host_addr = cl->host_client_id;
-	mei_hdr.me_addr = cl->me_client_id;
-	mei_hdr.reserved = 0;
-
-	if (*slots >= msg_slots) {
-		mei_hdr.length = len;
-		mei_hdr.msg_complete = 1;
-	/* Split the message only if we can write the whole host buffer */
-	} else if (*slots == dev->hbuf_depth) {
-		msg_slots = *slots;
-		len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
-		mei_hdr.length = len;
-		mei_hdr.msg_complete = 0;
-	} else {
-		/* wait for next time the host buffer is empty */
-		return 0;
-	}
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
 
-	dev_dbg(&dev->pdev->dev, "buf: size = %d idx = %lu\n",
-			cb->request_buffer.size, cb->buf_idx);
-	dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(&mei_hdr));
+	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
+	slots = mei_hbuf_empty_slots(dev);
 
-	*slots -=  msg_slots;
-	if (mei_write_message(dev, &mei_hdr,
-			cb->request_buffer.data + cb->buf_idx)) {
-		cl->status = -ENODEV;
-		list_move_tail(&cb->list, &cmpl_list->list);
-		return -ENODEV;
-	}
+	if (mei_cl_is_other_connecting(cl))
+		return 0;
 
-	if (mei_cl_flow_ctrl_reduce(cl))
-		return -ENODEV;
+	if (slots < msg_slots)
+		return -EMSGSIZE;
 
-	cl->status = 0;
-	cb->buf_idx += mei_hdr.length;
-	if (mei_hdr.msg_complete)
-		list_move_tail(&cb->list, &dev->write_waiting_list.list);
+	cl->state = MEI_FILE_CONNECTING;
 
+	ret = mei_hbm_cl_connect_req(dev, cl);
+	if (ret) {
+		cl->status = ret;
+		cb->buf_idx = 0;
+		list_del(&cb->list);
+		return ret;
+	}
+
+	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
+	cl->timer_count = MEI_CONNECT_TIMEOUT;
 	return 0;
 }
 
+
 /**
- * mei_irq_thread_read_handler - bottom half read routine after ISR to
+ * mei_irq_read_handler - bottom half read routine after ISR to
  * handle the read processing.
  *
  * @dev: the device structure
@@ -323,13 +328,11 @@ int mei_irq_read_handler(struct mei_device *dev,
 		struct mei_cl_cb *cmpl_list, s32 *slots)
 {
 	struct mei_msg_hdr *mei_hdr;
-	struct mei_cl *cl_pos = NULL;
-	struct mei_cl *cl_next = NULL;
-	int ret = 0;
+	struct mei_cl *cl;
+	int ret;
 
 	if (!dev->rd_msg_hdr) {
 		dev->rd_msg_hdr = mei_read_hdr(dev);
-		dev_dbg(&dev->pdev->dev, "slots =%08x.\n", *slots);
 		(*slots)--;
 		dev_dbg(&dev->pdev->dev, "slots =%08x.\n", *slots);
 	}
@@ -337,70 +340,74 @@ int mei_irq_read_handler(struct mei_device *dev,
 	dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 
 	if (mei_hdr->reserved || !dev->rd_msg_hdr) {
-		dev_dbg(&dev->pdev->dev, "corrupted message header.\n");
+		dev_err(&dev->pdev->dev, "corrupted message header 0x%08X\n",
+				dev->rd_msg_hdr);
 		ret = -EBADMSG;
 		goto end;
 	}
 
-	if (mei_hdr->host_addr || mei_hdr->me_addr) {
-		list_for_each_entry_safe(cl_pos, cl_next,
-					&dev->file_list, link) {
-			dev_dbg(&dev->pdev->dev,
-					"list_for_each_entry_safe read host"
-					" client = %d, ME client = %d\n",
-					cl_pos->host_client_id,
-					cl_pos->me_client_id);
-			if (cl_pos->host_client_id == mei_hdr->host_addr &&
-			    cl_pos->me_client_id == mei_hdr->me_addr)
-				break;
-		}
+	if (mei_slots2data(*slots) < mei_hdr->length) {
+		dev_err(&dev->pdev->dev, "less data available than length=%08x.\n",
+				*slots);
+		/* we can't read the message */
+		ret = -ENODATA;
+		goto end;
+	}
 
-		if (&cl_pos->link == &dev->file_list) {
-			dev_dbg(&dev->pdev->dev, "corrupted message header\n");
-			ret = -EBADMSG;
+	/*  HBM message */
+	if (mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0) {
+		ret = mei_hbm_dispatch(dev, mei_hdr);
+		if (ret) {
+			dev_dbg(&dev->pdev->dev, "mei_hbm_dispatch failed ret = %d\n",
+					ret);
 			goto end;
 		}
+		goto reset_slots;
 	}
-	if (((*slots) * sizeof(u32)) < mei_hdr->length) {
-		dev_dbg(&dev->pdev->dev,
-				"we can't read the message slots =%08x.\n",
-				*slots);
-		/* we can't read the message */
-		ret = -ERANGE;
-		goto end;
+
+	/* find recipient cl */
+	list_for_each_entry(cl, &dev->file_list, link) {
+		if (mei_cl_hbm_equal(cl, mei_hdr)) {
+			cl_dbg(dev, cl, "got a message\n");
+			break;
+		}
 	}
 
-	/* decide where to read the message too */
-	if (!mei_hdr->host_addr) {
-		dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_bus_message.\n");
-		mei_hbm_dispatch(dev, mei_hdr);
-		dev_dbg(&dev->pdev->dev, "end mei_irq_thread_read_bus_message.\n");
-	} else if (mei_hdr->host_addr == dev->iamthif_cl.host_client_id &&
-		   (MEI_FILE_CONNECTED == dev->iamthif_cl.state) &&
-		   (dev->iamthif_state == MEI_IAMTHIF_READING)) {
-		dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_iamthif_message.\n");
+	/* if no recipient cl was found we assume corrupted header */
+	if (&cl->link == &dev->file_list) {
+		dev_err(&dev->pdev->dev, "no destination client found 0x%08X\n",
+				dev->rd_msg_hdr);
+		ret = -EBADMSG;
+		goto end;
+	}
 
-		dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
+	if (mei_hdr->host_addr == dev->iamthif_cl.host_client_id &&
+	    MEI_FILE_CONNECTED == dev->iamthif_cl.state &&
+	    dev->iamthif_state == MEI_IAMTHIF_READING) {
 
-		ret = mei_amthif_irq_read_message(cmpl_list, dev, mei_hdr);
-		if (ret)
+		ret = mei_amthif_irq_read_msg(dev, mei_hdr, cmpl_list);
+		if (ret) {
+			dev_err(&dev->pdev->dev, "mei_amthif_irq_read_msg failed = %d\n",
+					ret);
 			goto end;
+		}
 	} else {
-		dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_client_message.\n");
-		ret = mei_irq_thread_read_client_message(cmpl_list,
-							 dev, mei_hdr);
-		if (ret)
+		ret = mei_cl_irq_read_msg(dev, mei_hdr, cmpl_list);
+		if (ret) {
+			dev_err(&dev->pdev->dev, "mei_cl_irq_read_msg failed = %d\n",
+					ret);
 			goto end;
-
+		}
 	}
 
+reset_slots:
 	/* reset the number of slots and header */
 	*slots = mei_count_full_read_slots(dev);
 	dev->rd_msg_hdr = 0;
 
 	if (*slots == -EOVERFLOW) {
 		/* overflow - reset */
-		dev_dbg(&dev->pdev->dev, "resetting due to slots overflow.\n");
+		dev_err(&dev->pdev->dev, "resetting due to slots overflow.\n");
 		/* set the event since message has been read */
 		ret = -ERANGE;
 		goto end;
@@ -408,6 +415,7 @@ int mei_irq_read_handler(struct mei_device *dev,
 end:
 	return ret;
 }
+EXPORT_SYMBOL_GPL(mei_irq_read_handler);
 
 
 /**
@@ -419,20 +427,19 @@ end:
  *
  * returns 0 on success, <0 on failure.
  */
-int mei_irq_write_handler(struct mei_device *dev,
-				struct mei_cl_cb *cmpl_list)
+int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
 {
 
 	struct mei_cl *cl;
-	struct mei_cl_cb *pos = NULL, *next = NULL;
+	struct mei_cl_cb *cb, *next;
 	struct mei_cl_cb *list;
 	s32 slots;
 	int ret;
 
-	if (!mei_hbuf_is_ready(dev)) {
-		dev_dbg(&dev->pdev->dev, "host buffer is not empty.\n");
+
+	if (!mei_hbuf_acquire(dev))
 		return 0;
-	}
+
 	slots = mei_hbuf_empty_slots(dev);
 	if (slots <= 0)
 		return -EMSGSIZE;
@@ -441,22 +448,21 @@ int mei_irq_write_handler(struct mei_device *dev,
 	dev_dbg(&dev->pdev->dev, "complete all waiting for write cb.\n");
 
 	list = &dev->write_waiting_list;
-	list_for_each_entry_safe(pos, next, &list->list, list) {
-		cl = pos->cl;
+	list_for_each_entry_safe(cb, next, &list->list, list) {
+		cl = cb->cl;
 		if (cl == NULL)
 			continue;
 
 		cl->status = 0;
-		list_del(&pos->list);
-		if (MEI_WRITING == cl->writing_state &&
-		    pos->fop_type == MEI_FOP_WRITE &&
+		list_del(&cb->list);
+		if (cb->fop_type == MEI_FOP_WRITE &&
 		    cl != &dev->iamthif_cl) {
-			dev_dbg(&dev->pdev->dev, "MEI WRITE COMPLETE\n");
+			cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
 			cl->writing_state = MEI_WRITE_COMPLETE;
-			list_add_tail(&pos->list, &cmpl_list->list);
+			list_add_tail(&cb->list, &cmpl_list->list);
 		}
 		if (cl == &dev->iamthif_cl) {
-			dev_dbg(&dev->pdev->dev, "check iamthif flow control.\n");
+			cl_dbg(dev, cl, "check iamthif flow control.\n");
 			if (dev->iamthif_flow_control_pending) {
 				ret = mei_amthif_irq_read(dev, &slots);
 				if (ret)
@@ -467,68 +473,55 @@ int mei_irq_write_handler(struct mei_device *dev,
 
 	if (dev->wd_state == MEI_WD_STOPPING) {
 		dev->wd_state = MEI_WD_IDLE;
-		wake_up_interruptible(&dev->wait_stop_wd);
+		wake_up(&dev->wait_stop_wd);
 	}
 
-	if (dev->wr_ext_msg.hdr.length) {
-		mei_write_message(dev, &dev->wr_ext_msg.hdr,
-				dev->wr_ext_msg.data);
-		slots -= mei_data2slots(dev->wr_ext_msg.hdr.length);
-		dev->wr_ext_msg.hdr.length = 0;
-	}
-	if (dev->dev_state == MEI_DEV_ENABLED) {
+	if (mei_cl_is_connected(&dev->wd_cl)) {
 		if (dev->wd_pending &&
 		    mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
-			if (mei_wd_send(dev))
-				dev_dbg(&dev->pdev->dev, "wd send failed.\n");
-			else if (mei_cl_flow_ctrl_reduce(&dev->wd_cl))
-				return -ENODEV;
-
+			ret = mei_wd_send(dev);
+			if (ret)
+				return ret;
 			dev->wd_pending = false;
-
-			if (dev->wd_state == MEI_WD_RUNNING)
-				slots -= mei_data2slots(MEI_WD_START_MSG_SIZE);
-			else
-				slots -= mei_data2slots(MEI_WD_STOP_MSG_SIZE);
 		}
 	}
 
 	/* complete control write list CB */
 	dev_dbg(&dev->pdev->dev, "complete control write list cb.\n");
-	list_for_each_entry_safe(pos, next, &dev->ctrl_wr_list.list, list) {
-		cl = pos->cl;
+	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
+		cl = cb->cl;
 		if (!cl) {
-			list_del(&pos->list);
+			list_del(&cb->list);
 			return -ENODEV;
 		}
-		switch (pos->fop_type) {
+		switch (cb->fop_type) {
 		case MEI_FOP_CLOSE:
 			/* send disconnect message */
-			ret = _mei_irq_thread_close(dev, &slots, pos,
-						cl, cmpl_list);
+			ret = mei_cl_irq_close(cl, cb, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
 		case MEI_FOP_READ:
 			/* send flow control message */
-			ret = _mei_irq_thread_read(dev, &slots, pos,
-						cl, cmpl_list);
+			ret = mei_cl_irq_read(cl, cb, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
-		case MEI_FOP_IOCTL:
+		case MEI_FOP_CONNECT:
 			/* connect message */
-			if (mei_cl_is_other_connecting(cl))
-				continue;
-			ret = _mei_irq_thread_ioctl(dev, &slots, pos,
-						cl, cmpl_list);
+			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
-
+		case MEI_FOP_DISCONNECT_RSP:
+			/* send disconnect resp */
+			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+			break;
 		default:
 			BUG();
 		}
@@ -536,29 +529,20 @@ int mei_irq_write_handler(struct mei_device *dev,
 	}
 	/* complete  write list CB */
 	dev_dbg(&dev->pdev->dev, "complete write list cb.\n");
-	list_for_each_entry_safe(pos, next, &dev->write_list.list, list) {
-		cl = pos->cl;
+	list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
+		cl = cb->cl;
 		if (cl == NULL)
 			continue;
-		if (mei_cl_flow_ctrl_creds(cl) <= 0) {
-			dev_dbg(&dev->pdev->dev,
-				"No flow control credentials for client %d, not sending.\n",
-				cl->host_client_id);
-			continue;
-		}
-
 		if (cl == &dev->iamthif_cl)
-			ret = mei_amthif_irq_write_complete(dev, &slots,
-							pos, cmpl_list);
+			ret = mei_amthif_irq_write(cl, cb, cmpl_list);
 		else
-			ret = mei_irq_thread_write_complete(dev, &slots, pos,
-						cmpl_list);
+			ret = mei_cl_irq_write(cl, cb, cmpl_list);
 		if (ret)
 			return ret;
-
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(mei_irq_write_handler);
 
 
 
@@ -567,13 +551,11 @@ int mei_irq_write_handler(struct mei_device *dev,
  *
  * @work: pointer to the work_struct structure
  *
- * NOTE: This function is called by timer interrupt work
  */
 void mei_timer(struct work_struct *work)
 {
 	unsigned long timeout;
-	struct mei_cl *cl_pos = NULL;
-	struct mei_cl *cl_next = NULL;
+	struct mei_cl *cl;
 	struct mei_cl_cb  *cb_pos = NULL;
 	struct mei_cl_cb  *cb_next = NULL;
 
@@ -582,33 +564,42 @@ void mei_timer(struct work_struct *work)
 
 
 	mutex_lock(&dev->device_lock);
-	if (dev->dev_state != MEI_DEV_ENABLED) {
-		if (dev->dev_state == MEI_DEV_INIT_CLIENTS) {
-			if (dev->init_clients_timer) {
-				if (--dev->init_clients_timer == 0) {
-					dev_dbg(&dev->pdev->dev, "IMEI reset due to init clients timeout ,init clients state = %d.\n",
-						dev->init_clients_state);
-					mei_reset(dev, 1);
-				}
+
+	/* Catch interrupt stalls during HBM init handshake */
+	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
+	    dev->hbm_state != MEI_HBM_IDLE) {
+
+		if (dev->init_clients_timer) {
+			if (--dev->init_clients_timer == 0) {
+				dev_err(&dev->pdev->dev, "timer: init clients timeout hbm_state = %d.\n",
+					dev->hbm_state);
+				mei_reset(dev);
+				goto out;
 			}
 		}
-		goto out;
 	}
+
+	if (dev->dev_state != MEI_DEV_ENABLED)
+		goto out;
+
 	/*** connect/disconnect timeouts ***/
-	list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
-		if (cl_pos->timer_count) {
-			if (--cl_pos->timer_count == 0) {
-				dev_dbg(&dev->pdev->dev, "HECI reset due to connect/disconnect timeout.\n");
-				mei_reset(dev, 1);
+	list_for_each_entry(cl, &dev->file_list, link) {
+		if (cl->timer_count) {
+			if (--cl->timer_count == 0) {
+				dev_err(&dev->pdev->dev, "timer: connect/disconnect timeout.\n");
+				mei_reset(dev);
 				goto out;
 			}
 		}
 	}
 
+	if (!mei_cl_is_connected(&dev->iamthif_cl))
+		goto out;
+
 	if (dev->iamthif_stall_timer) {
 		if (--dev->iamthif_stall_timer == 0) {
-			dev_dbg(&dev->pdev->dev, "resetting because of hang to amthi.\n");
-			mei_reset(dev, 1);
+			dev_err(&dev->pdev->dev, "timer: amthif  hanged.\n");
+			mei_reset(dev);
 			dev->iamthif_msg_buf_size = 0;
 			dev->iamthif_msg_buf_index = 0;
 			dev->iamthif_canceled = false;
@@ -644,10 +635,10 @@ void mei_timer(struct work_struct *work)
 			list_for_each_entry_safe(cb_pos, cb_next,
 				&dev->amthif_rd_complete_list.list, list) {
 
-				cl_pos = cb_pos->file_object->private_data;
+				cl = cb_pos->file_object->private_data;
 
 				/* Finding the AMTHI entry. */
-				if (cl_pos == &dev->iamthif_cl)
+				if (cl == &dev->iamthif_cl)
 					list_del(&cb_pos->list);
 			}
 			mei_io_cb_free(dev->iamthif_current_cb);
@@ -661,7 +652,8 @@ void mei_timer(struct work_struct *work)
 		}
 	}
 out:
-	schedule_delayed_work(&dev->timer_work, 2 * HZ);
+	if (dev->dev_state != MEI_DEV_DISABLED)
+		schedule_delayed_work(&dev->timer_work, 2 * HZ);
 	mutex_unlock(&dev->device_lock);
 }