1 files changed, 376 insertions, 220 deletions

diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index 0a0448326e9..804106209d7 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -14,54 +14,111 @@
  *
  */
 
+#include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
 #include <linux/mei.h>
+#include <linux/pm_runtime.h>
 
 #include "mei_dev.h"
 #include "hbm.h"
-#include "hw-me.h"
+#include "client.h"
+
+static const char *mei_cl_conn_status_str(enum mei_cl_connect_status status)
+{
+#define MEI_CL_CS(status) case MEI_CL_CONN_##status: return #status
+	switch (status) {
+	MEI_CL_CS(SUCCESS);
+	MEI_CL_CS(NOT_FOUND);
+	MEI_CL_CS(ALREADY_STARTED);
+	MEI_CL_CS(OUT_OF_RESOURCES);
+	MEI_CL_CS(MESSAGE_SMALL);
+	default: return "unknown";
+	}
+#undef MEI_CL_CCS
+}
+
+/**
+ * mei_cl_conn_status_to_errno - convert client connect response
+ * status to error code
+ *
+ * @status: client connect response status
+ *
+ * returns corresponding error code
+ */
+static int mei_cl_conn_status_to_errno(enum mei_cl_connect_status status)
+{
+	switch (status) {
+	case MEI_CL_CONN_SUCCESS:          return 0;
+	case MEI_CL_CONN_NOT_FOUND:        return -ENOTTY;
+	case MEI_CL_CONN_ALREADY_STARTED:  return -EBUSY;
+	case MEI_CL_CONN_OUT_OF_RESOURCES: return -EBUSY;
+	case MEI_CL_CONN_MESSAGE_SMALL:    return -EINVAL;
+	default:                           return -EINVAL;
+	}
+}
+
+/**
+ * mei_hbm_idle - set hbm to idle state
+ *
+ * @dev: the device structure
+ */
+void mei_hbm_idle(struct mei_device *dev)
+{
+	dev->init_clients_timer = 0;
+	dev->hbm_state = MEI_HBM_IDLE;
+}
+
+/**
+ * mei_hbm_reset - reset hbm counters and book keeping data structurs
+ *
+ * @dev: the device structure
+ */
+void mei_hbm_reset(struct mei_device *dev)
+{
+	dev->me_clients_num = 0;
+	dev->me_client_presentation_num = 0;
+	dev->me_client_index = 0;
+
+	kfree(dev->me_clients);
+	dev->me_clients = NULL;
+
+	mei_hbm_idle(dev);
+}
 
 /**
  * mei_hbm_me_cl_allocate - allocates storage for me clients
  *
  * @dev: the device structure
  *
- * returns none.
+ * returns 0 on success -ENOMEM on allocation failure
  */
-static void mei_hbm_me_cl_allocate(struct mei_device *dev)
+static int mei_hbm_me_cl_allocate(struct mei_device *dev)
 {
 	struct mei_me_client *clients;
 	int b;
 
-	dev->me_clients_num = 0;
-	dev->me_client_presentation_num = 0;
-	dev->me_client_index = 0;
+	mei_hbm_reset(dev);
 
 	/* count how many ME clients we have */
 	for_each_set_bit(b, dev->me_clients_map, MEI_CLIENTS_MAX)
 		dev->me_clients_num++;
 
 	if (dev->me_clients_num == 0)
-		return;
-
-	kfree(dev->me_clients);
-	dev->me_clients = NULL;
+		return 0;
 
-	dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%zd.\n",
+	dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%ld.\n",
 		dev->me_clients_num * sizeof(struct mei_me_client));
 	/* allocate storage for ME clients representation */
 	clients = kcalloc(dev->me_clients_num,
 			sizeof(struct mei_me_client), GFP_KERNEL);
 	if (!clients) {
 		dev_err(&dev->pdev->dev, "memory allocation for ME clients failed.\n");
-		dev->dev_state = MEI_DEV_RESETTING;
-		mei_reset(dev, 1);
-		return;
+		return -ENOMEM;
 	}
 	dev->me_clients = clients;
-	return;
+	return 0;
 }
 
 /**
@@ -85,12 +142,12 @@ void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
 }
 
 /**
- * same_disconn_addr - tells if they have the same address
+ * mei_hbm_cl_addr_equal - tells if they have the same address
  *
- * @file: private data of the file object.
- * @disconn: disconnection request.
+ * @cl: - client
+ * @buf: buffer with cl header
  *
- * returns true if addres are same
+ * returns true if addresses are the same
  */
 static inline
 bool mei_hbm_cl_addr_equal(struct mei_cl *cl, void *buf)
@@ -101,33 +158,6 @@ bool mei_hbm_cl_addr_equal(struct mei_cl *cl, void *buf)
 }
 
 
-/**
- * is_treat_specially_client - checks if the message belongs
- * to the file private data.
- *
- * @cl: private data of the file object
- * @rs: connect response bus message
- *
- */
-static bool is_treat_specially_client(struct mei_cl *cl,
-		struct hbm_client_connect_response *rs)
-{
-	if (mei_hbm_cl_addr_equal(cl, rs)) {
-		if (!rs->status) {
-			cl->state = MEI_FILE_CONNECTED;
-			cl->status = 0;
-
-		} else {
-			cl->state = MEI_FILE_DISCONNECTED;
-			cl->status = -ENODEV;
-		}
-		cl->timer_count = 0;
-
-		return true;
-	}
-	return false;
-}
-
 int mei_hbm_start_wait(struct mei_device *dev)
 {
 	int ret;
@@ -137,14 +167,14 @@ int mei_hbm_start_wait(struct mei_device *dev)
 	mutex_unlock(&dev->device_lock);
 	ret = wait_event_interruptible_timeout(dev->wait_recvd_msg,
 			dev->hbm_state == MEI_HBM_IDLE ||
-			dev->hbm_state > MEI_HBM_START,
-			mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
+			dev->hbm_state >= MEI_HBM_STARTED,
+			mei_secs_to_jiffies(MEI_HBM_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
 	if (ret <= 0 && (dev->hbm_state <= MEI_HBM_START)) {
 		dev->hbm_state = MEI_HBM_IDLE;
 		dev_err(&dev->pdev->dev, "waiting for mei start failed\n");
-		return -ETIMEDOUT;
+		return -ETIME;
 	}
 	return 0;
 }
@@ -153,12 +183,15 @@ int mei_hbm_start_wait(struct mei_device *dev)
  * mei_hbm_start_req - sends start request message.
  *
  * @dev: the device structure
+ *
+ * returns 0 on success and < 0 on failure
  */
 int mei_hbm_start_req(struct mei_device *dev)
 {
 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
 	struct hbm_host_version_request *start_req;
 	const size_t len = sizeof(struct hbm_host_version_request);
+	int ret;
 
 	mei_hbm_hdr(mei_hdr, len);
 
@@ -170,12 +203,13 @@ int mei_hbm_start_req(struct mei_device *dev)
 	start_req->host_version.minor_version = HBM_MINOR_VERSION;
 
 	dev->hbm_state = MEI_HBM_IDLE;
-	if (mei_write_message(dev, mei_hdr, dev->wr_msg.data)) {
-		dev_err(&dev->pdev->dev, "version message write failed\n");
-		dev->dev_state = MEI_DEV_RESETTING;
-		mei_reset(dev, 1);
-		return -ENODEV;
+	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "version message write failed: ret = %d\n",
+			ret);
+		return ret;
 	}
+
 	dev->hbm_state = MEI_HBM_START;
 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 	return 0;
@@ -186,13 +220,15 @@ int mei_hbm_start_req(struct mei_device *dev)
  *
  * @dev: the device structure
  *
- * returns none.
+ * returns 0 on success and < 0 on failure
  */
-static void mei_hbm_enum_clients_req(struct mei_device *dev)
+static int mei_hbm_enum_clients_req(struct mei_device *dev)
 {
 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
 	struct hbm_host_enum_request *enum_req;
 	const size_t len = sizeof(struct hbm_host_enum_request);
+	int ret;
+
 	/* enumerate clients */
 	mei_hbm_hdr(mei_hdr, len);
 
@@ -200,14 +236,15 @@ static void mei_hbm_enum_clients_req(struct mei_device *dev)
 	memset(enum_req, 0, len);
 	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
 
-	if (mei_write_message(dev, mei_hdr, dev->wr_msg.data)) {
-		dev->dev_state = MEI_DEV_RESETTING;
-		dev_err(&dev->pdev->dev, "enumeration request write failed.\n");
-		mei_reset(dev, 1);
+	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "enumeration request write failed: ret = %d.\n",
+			ret);
+		return ret;
 	}
 	dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
-	return;
+	return 0;
 }
 
 /**
@@ -215,7 +252,7 @@ static void mei_hbm_enum_clients_req(struct mei_device *dev)
  *
  * @dev: the device structure
  *
- * returns none.
+ * returns 0 on success and < 0 on failure
  */
 
 static int mei_hbm_prop_req(struct mei_device *dev)
@@ -226,7 +263,7 @@ static int mei_hbm_prop_req(struct mei_device *dev)
 	const size_t len = sizeof(struct hbm_props_request);
 	unsigned long next_client_index;
 	unsigned long client_num;
-
+	int ret;
 
 	client_num = dev->me_client_presentation_num;
 
@@ -253,12 +290,11 @@ static int mei_hbm_prop_req(struct mei_device *dev)
 	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
 	prop_req->address = next_client_index;
 
-	if (mei_write_message(dev, mei_hdr, dev->wr_msg.data)) {
-		dev->dev_state = MEI_DEV_RESETTING;
-		dev_err(&dev->pdev->dev, "properties request write failed\n");
-		mei_reset(dev, 1);
-
-		return -EIO;
+	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "properties request write failed: ret = %d\n",
+			ret);
+		return ret;
 	}
 
 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
@@ -267,18 +303,47 @@ static int mei_hbm_prop_req(struct mei_device *dev)
 	return 0;
 }
 
+/*
+ * mei_hbm_pg - sends pg command
+ *
+ * @dev: the device structure
+ * @pg_cmd: the pg command code
+ *
+ * This function returns -EIO on write failure
+ */
+int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
+{
+	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
+	struct hbm_power_gate *req;
+	const size_t len = sizeof(struct hbm_power_gate);
+	int ret;
+
+	mei_hbm_hdr(mei_hdr, len);
+
+	req = (struct hbm_power_gate *)dev->wr_msg.data;
+	memset(req, 0, len);
+	req->hbm_cmd = pg_cmd;
+
+	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+	if (ret)
+		dev_err(&dev->pdev->dev, "power gate command write failed.\n");
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mei_hbm_pg);
+
 /**
- * mei_hbm_stop_req_prepare - perpare stop request message
+ * mei_hbm_stop_req - send stop request message
  *
  * @dev - mei device
- * @mei_hdr - mei message header
- * @data - hbm message body buffer
+ * @cl: client info
+ *
+ * This function returns -EIO on write failure
  */
-static void mei_hbm_stop_req_prepare(struct mei_device *dev,
-		struct mei_msg_hdr *mei_hdr, unsigned char *data)
+static int mei_hbm_stop_req(struct mei_device *dev)
 {
+	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
 	struct hbm_host_stop_request *req =
-			(struct hbm_host_stop_request *)data;
+			(struct hbm_host_stop_request *)dev->wr_msg.data;
 	const size_t len = sizeof(struct hbm_host_stop_request);
 
 	mei_hbm_hdr(mei_hdr, len);
@@ -286,10 +351,12 @@ static void mei_hbm_stop_req_prepare(struct mei_device *dev,
 	memset(req, 0, len);
 	req->hbm_cmd = HOST_STOP_REQ_CMD;
 	req->reason = DRIVER_STOP_REQUEST;
+
+	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
 }
 
 /**
- * mei_hbm_cl_flow_control_req - sends flow control requst.
+ * mei_hbm_cl_flow_control_req - sends flow control request.
  *
  * @dev: the device structure
  * @cl: client info
@@ -304,8 +371,7 @@ int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
 	mei_hbm_hdr(mei_hdr, len);
 	mei_hbm_cl_hdr(cl, MEI_FLOW_CONTROL_CMD, dev->wr_msg.data, len);
 
-	dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
-		cl->host_client_id, cl->me_client_id);
+	cl_dbg(dev, cl, "sending flow control\n");
 
 	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
 }
@@ -315,27 +381,34 @@ int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
  *
  * @dev: the device structure
  * @flow: flow control.
+ *
+ * return 0 on success, < 0 otherwise
  */
-static void mei_hbm_add_single_flow_creds(struct mei_device *dev,
+static int mei_hbm_add_single_flow_creds(struct mei_device *dev,
 				  struct hbm_flow_control *flow)
 {
-	struct mei_me_client *client;
-	int i;
-
-	for (i = 0; i < dev->me_clients_num; i++) {
-		client = &dev->me_clients[i];
-		if (client && flow->me_addr == client->client_id) {
-			if (client->props.single_recv_buf) {
-				client->mei_flow_ctrl_creds++;
-				dev_dbg(&dev->pdev->dev, "recv flow ctrl msg ME %d (single).\n",
-				    flow->me_addr);
-				dev_dbg(&dev->pdev->dev, "flow control credentials =%d.\n",
-				    client->mei_flow_ctrl_creds);
-			} else {
-				BUG();	/* error in flow control */
-			}
-		}
+	struct mei_me_client *me_cl;
+	int id;
+
+	id = mei_me_cl_by_id(dev, flow->me_addr);
+	if (id < 0) {
+		dev_err(&dev->pdev->dev, "no such me client %d\n",
+			flow->me_addr);
+		return id;
+	}
+
+	me_cl = &dev->me_clients[id];
+	if (me_cl->props.single_recv_buf) {
+		me_cl->mei_flow_ctrl_creds++;
+		dev_dbg(&dev->pdev->dev, "recv flow ctrl msg ME %d (single).\n",
+		    flow->me_addr);
+		dev_dbg(&dev->pdev->dev, "flow control credentials =%d.\n",
+		    me_cl->mei_flow_ctrl_creds);
+	} else {
+		BUG();	/* error in flow control */
 	}
+
+	return 0;
 }
 
 /**
@@ -347,8 +420,7 @@ static void mei_hbm_add_single_flow_creds(struct mei_device *dev,
 static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
 		struct hbm_flow_control *flow_control)
 {
-	struct mei_cl *cl = NULL;
-	struct mei_cl *next = NULL;
+	struct mei_cl *cl;
 
 	if (!flow_control->host_addr) {
 		/* single receive buffer */
@@ -357,7 +429,7 @@ static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
 	}
 
 	/* normal connection */
-	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
+	list_for_each_entry(cl, &dev->file_list, link) {
 		if (mei_hbm_cl_addr_equal(cl, flow_control)) {
 			cl->mei_flow_ctrl_creds++;
 			dev_dbg(&dev->pdev->dev, "flow ctrl msg for host %d ME %d.\n",
@@ -390,6 +462,25 @@ int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
 }
 
 /**
+ * mei_hbm_cl_disconnect_rsp - sends disconnect respose to the FW
+ *
+ * @dev: the device structure
+ * @cl: a client to disconnect from
+ *
+ * This function returns -EIO on write failure
+ */
+int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
+{
+	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
+	const size_t len = sizeof(struct hbm_client_connect_response);
+
+	mei_hbm_hdr(mei_hdr, len);
+	mei_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD, dev->wr_msg.data, len);
+
+	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+}
+
+/**
  * mei_hbm_cl_disconnect_res - disconnect response from ME
  *
  * @dev: the device structure
@@ -399,29 +490,23 @@ static void mei_hbm_cl_disconnect_res(struct mei_device *dev,
 		struct hbm_client_connect_response *rs)
 {
 	struct mei_cl *cl;
-	struct mei_cl_cb *pos = NULL, *next = NULL;
-
-	dev_dbg(&dev->pdev->dev,
-			"disconnect_response:\n"
-			"ME Client = %d\n"
-			"Host Client = %d\n"
-			"Status = %d\n",
-			rs->me_addr,
-			rs->host_addr,
-			rs->status);
-
-	list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
-		cl = pos->cl;
-
-		if (!cl) {
-			list_del(&pos->list);
+	struct mei_cl_cb *cb, *next;
+
+	dev_dbg(&dev->pdev->dev, "hbm: disconnect response cl:host=%02d me=%02d status=%d\n",
+			rs->me_addr, rs->host_addr, rs->status);
+
+	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list.list, list) {
+		cl = cb->cl;
+
+		/* this should not happen */
+		if (WARN_ON(!cl)) {
+			list_del(&cb->list);
 			return;
 		}
 
-		dev_dbg(&dev->pdev->dev, "list_for_each_entry_safe in ctrl_rd_list.\n");
 		if (mei_hbm_cl_addr_equal(cl, rs)) {
-			list_del(&pos->list);
-			if (!rs->status)
+			list_del(&cb->list);
+			if (rs->status == MEI_CL_DISCONN_SUCCESS)
 				cl->state = MEI_FILE_DISCONNECTED;
 
 			cl->status = 0;
@@ -451,7 +536,7 @@ int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
 }
 
 /**
- * mei_hbm_cl_connect_res - connect resposne from the ME
+ * mei_hbm_cl_connect_res - connect response from the ME
  *
  * @dev: the device structure
  * @rs: connect response bus message
@@ -461,81 +546,78 @@ static void mei_hbm_cl_connect_res(struct mei_device *dev,
 {
 
 	struct mei_cl *cl;
-	struct mei_cl_cb *pos = NULL, *next = NULL;
+	struct mei_cl_cb *cb, *next;
 
-	dev_dbg(&dev->pdev->dev,
-			"connect_response:\n"
-			"ME Client = %d\n"
-			"Host Client = %d\n"
-			"Status = %d\n",
-			rs->me_addr,
-			rs->host_addr,
-			rs->status);
+	dev_dbg(&dev->pdev->dev, "hbm: connect response cl:host=%02d me=%02d status=%s\n",
+			rs->me_addr, rs->host_addr,
+			mei_cl_conn_status_str(rs->status));
 
-	/* if WD or iamthif client treat specially */
+	cl = NULL;
 
-	if (is_treat_specially_client(&dev->wd_cl, rs)) {
-		dev_dbg(&dev->pdev->dev, "successfully connected to WD client.\n");
-		mei_watchdog_register(dev);
+	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list.list, list) {
 
-		return;
-	}
+		cl = cb->cl;
+		/* this should not happen */
+		if (WARN_ON(!cl)) {
+			list_del_init(&cb->list);
+			continue;
+		}
 
-	if (is_treat_specially_client(&dev->iamthif_cl, rs)) {
-		dev->iamthif_state = MEI_IAMTHIF_IDLE;
-		return;
-	}
-	list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
+		if (cb->fop_type !=  MEI_FOP_CONNECT)
+			continue;
 
-		cl = pos->cl;
-		if (!cl) {
-			list_del(&pos->list);
-			return;
-		}
-		if (pos->fop_type == MEI_FOP_IOCTL) {
-			if (is_treat_specially_client(cl, rs)) {
-				list_del(&pos->list);
-				cl->status = 0;
-				cl->timer_count = 0;
-				break;
-			}
+		if (mei_hbm_cl_addr_equal(cl, rs)) {
+			list_del(&cb->list);
+			break;
 		}
 	}
+
+	if (!cl)
+		return;
+
+	cl->timer_count = 0;
+	if (rs->status == MEI_CL_CONN_SUCCESS)
+		cl->state = MEI_FILE_CONNECTED;
+	else
+		cl->state = MEI_FILE_DISCONNECTED;
+	cl->status = mei_cl_conn_status_to_errno(rs->status);
 }
 
 
 /**
- * mei_hbm_fw_disconnect_req - disconnect request initiated by me
- *  host sends disoconnect response
+ * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
+ *  host sends disconnect response
  *
  * @dev: the device structure.
  * @disconnect_req: disconnect request bus message from the me
+ *
+ * returns -ENOMEM on allocation failure
  */
-static void mei_hbm_fw_disconnect_req(struct mei_device *dev,
+static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
 		struct hbm_client_connect_request *disconnect_req)
 {
-	struct mei_cl *cl, *next;
-	const size_t len = sizeof(struct hbm_client_connect_response);
+	struct mei_cl *cl;
+	struct mei_cl_cb *cb;
 
-	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
+	list_for_each_entry(cl, &dev->file_list, link) {
 		if (mei_hbm_cl_addr_equal(cl, disconnect_req)) {
 			dev_dbg(&dev->pdev->dev, "disconnect request host client %d ME client %d.\n",
 					disconnect_req->host_addr,
 					disconnect_req->me_addr);
 			cl->state = MEI_FILE_DISCONNECTED;
 			cl->timer_count = 0;
-			if (cl == &dev->wd_cl)
-				dev->wd_pending = false;
-			else if (cl == &dev->iamthif_cl)
-				dev->iamthif_timer = 0;
-
-			/* prepare disconnect response */
-			mei_hbm_hdr(&dev->wr_ext_msg.hdr, len);
-			mei_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD,
-					 dev->wr_ext_msg.data, len);
+
+			cb = mei_io_cb_init(cl, NULL);
+			if (!cb)
+				return -ENOMEM;
+			cb->fop_type = MEI_FOP_DISCONNECT_RSP;
+			cl_dbg(dev, cl, "add disconnect response as first\n");
+			list_add(&cb->list, &dev->ctrl_wr_list.list);
+
 			break;
 		}
 	}
+	return 0;
 }
 
 
@@ -559,8 +641,10 @@ bool mei_hbm_version_is_supported(struct mei_device *dev)
  *
  * @dev: the device structure
  * @mei_hdr: header of bus message
+ *
+ * returns 0 on success and < 0 on failure
  */
-void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
+int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 {
 	struct mei_bus_message *mei_msg;
 	struct mei_me_client *me_client;
@@ -577,8 +661,20 @@ void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
 
+	/* ignore spurious message and prevent reset nesting
+	 * hbm is put to idle during system reset
+	 */
+	if (dev->hbm_state == MEI_HBM_IDLE) {
+		dev_dbg(&dev->pdev->dev, "hbm: state is idle ignore spurious messages\n");
+		return 0;
+	}
+
 	switch (mei_msg->hbm_cmd) {
 	case HOST_START_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: start: response message received.\n");
+
+		dev->init_clients_timer = 0;
+
 		version_res = (struct hbm_host_version_response *)mei_msg;
 
 		dev_dbg(&dev->pdev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
@@ -597,73 +693,107 @@ void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 		}
 
 		if (!mei_hbm_version_is_supported(dev)) {
-			dev_warn(&dev->pdev->dev, "hbm version mismatch: stopping the driver.\n");
+			dev_warn(&dev->pdev->dev, "hbm: start: version mismatch - stopping the driver.\n");
 
-			dev->hbm_state = MEI_HBM_STOP;
-			mei_hbm_stop_req_prepare(dev, &dev->wr_msg.hdr,
-						dev->wr_msg.data);
-			mei_write_message(dev, &dev->wr_msg.hdr,
-					dev->wr_msg.data);
+			dev->hbm_state = MEI_HBM_STOPPED;
+			if (mei_hbm_stop_req(dev)) {
+				dev_err(&dev->pdev->dev, "hbm: start: failed to send stop request\n");
+				return -EIO;
+			}
+			break;
+		}
 
-			return;
+		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
+		    dev->hbm_state != MEI_HBM_START) {
+			dev_err(&dev->pdev->dev, "hbm: start: state mismatch, [%d, %d]\n",
+				dev->dev_state, dev->hbm_state);
+			return -EPROTO;
 		}
 
-		if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
-		    dev->hbm_state == MEI_HBM_START) {
-			dev->init_clients_timer = 0;
-			mei_hbm_enum_clients_req(dev);
-		} else {
-			dev_err(&dev->pdev->dev, "reset: wrong host start response\n");
-			mei_reset(dev, 1);
-			return;
+		dev->hbm_state = MEI_HBM_STARTED;
+
+		if (mei_hbm_enum_clients_req(dev)) {
+			dev_err(&dev->pdev->dev, "hbm: start: failed to send enumeration request\n");
+			return -EIO;
 		}
 
 		wake_up_interruptible(&dev->wait_recvd_msg);
-		dev_dbg(&dev->pdev->dev, "host start response message received.\n");
 		break;
 
 	case CLIENT_CONNECT_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: client connect response: message received.\n");
+
 		connect_res = (struct hbm_client_connect_response *) mei_msg;
 		mei_hbm_cl_connect_res(dev, connect_res);
-		dev_dbg(&dev->pdev->dev, "client connect response message received.\n");
 		wake_up(&dev->wait_recvd_msg);
 		break;
 
 	case CLIENT_DISCONNECT_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: client disconnect response: message received.\n");
+
 		disconnect_res = (struct hbm_client_connect_response *) mei_msg;
 		mei_hbm_cl_disconnect_res(dev, disconnect_res);
-		dev_dbg(&dev->pdev->dev, "client disconnect response message received.\n");
 		wake_up(&dev->wait_recvd_msg);
 		break;
 
 	case MEI_FLOW_CONTROL_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: client flow control response: message received.\n");
+
 		flow_control = (struct hbm_flow_control *) mei_msg;
 		mei_hbm_cl_flow_control_res(dev, flow_control);
-		dev_dbg(&dev->pdev->dev, "client flow control response message received.\n");
+		break;
+
+	case MEI_PG_ISOLATION_ENTRY_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "power gate isolation entry response received\n");
+		dev->pg_event = MEI_PG_EVENT_RECEIVED;
+		if (waitqueue_active(&dev->wait_pg))
+			wake_up(&dev->wait_pg);
+		break;
+
+	case MEI_PG_ISOLATION_EXIT_REQ_CMD:
+		dev_dbg(&dev->pdev->dev, "power gate isolation exit request received\n");
+		dev->pg_event = MEI_PG_EVENT_RECEIVED;
+		if (waitqueue_active(&dev->wait_pg))
+			wake_up(&dev->wait_pg);
+		else
+			/*
+			* If the driver is not waiting on this then
+			* this is HW initiated exit from PG.
+			* Start runtime pm resume sequence to exit from PG.
+			*/
+			pm_request_resume(&dev->pdev->dev);
 		break;
 
 	case HOST_CLIENT_PROPERTIES_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: properties response: message received.\n");
+
+		dev->init_clients_timer = 0;
+
+		if (dev->me_clients == NULL) {
+			dev_err(&dev->pdev->dev, "hbm: properties response: mei_clients not allocated\n");
+			return -EPROTO;
+		}
+
 		props_res = (struct hbm_props_response *)mei_msg;
 		me_client = &dev->me_clients[dev->me_client_presentation_num];
 
-		if (props_res->status || !dev->me_clients) {
-			dev_err(&dev->pdev->dev, "reset: properties response hbm wrong status.\n");
-			mei_reset(dev, 1);
-			return;
+		if (props_res->status) {
+			dev_err(&dev->pdev->dev, "hbm: properties response: wrong status = %d\n",
+				props_res->status);
+			return -EPROTO;
 		}
 
 		if (me_client->client_id != props_res->address) {
-			dev_err(&dev->pdev->dev, "reset: host properties response address mismatch\n");
-			mei_reset(dev, 1);
-			return;
+			dev_err(&dev->pdev->dev, "hbm: properties response: address mismatch %d ?= %d\n",
+				me_client->client_id, props_res->address);
+			return -EPROTO;
 		}
 
 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
 		    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
-			dev_err(&dev->pdev->dev, "reset: unexpected properties response\n");
-			mei_reset(dev, 1);
-
-			return;
+			dev_err(&dev->pdev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
+				dev->dev_state, dev->hbm_state);
+			return -EPROTO;
 		}
 
 		me_client->props = props_res->client_properties;
@@ -671,53 +801,79 @@ void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 		dev->me_client_presentation_num++;
 
 		/* request property for the next client */
-		mei_hbm_prop_req(dev);
+		if (mei_hbm_prop_req(dev))
+			return -EIO;
 
 		break;
 
 	case HOST_ENUM_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: enumeration response: message received\n");
+
+		dev->init_clients_timer = 0;
+
 		enum_res = (struct hbm_host_enum_response *) mei_msg;
-		memcpy(dev->me_clients_map, enum_res->valid_addresses, 32);
-		if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
-		    dev->hbm_state == MEI_HBM_ENUM_CLIENTS) {
-				dev->init_clients_timer = 0;
-				mei_hbm_me_cl_allocate(dev);
-				dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
-
-				/* first property reqeust */
-				mei_hbm_prop_req(dev);
-		} else {
-			dev_err(&dev->pdev->dev, "reset: unexpected enumeration response hbm.\n");
-			mei_reset(dev, 1);
-			return;
+		BUILD_BUG_ON(sizeof(dev->me_clients_map)
+				< sizeof(enum_res->valid_addresses));
+		memcpy(dev->me_clients_map, enum_res->valid_addresses,
+			sizeof(enum_res->valid_addresses));
+
+		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
+		    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
+			dev_err(&dev->pdev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
+				dev->dev_state, dev->hbm_state);
+			return -EPROTO;
 		}
+
+		if (mei_hbm_me_cl_allocate(dev)) {
+			dev_err(&dev->pdev->dev, "hbm: enumeration response: cannot allocate clients array\n");
+			return -ENOMEM;
+		}
+
+		dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
+
+		/* first property request */
+		if (mei_hbm_prop_req(dev))
+			return -EIO;
+
 		break;
 
 	case HOST_STOP_RES_CMD:
+		dev_dbg(&dev->pdev->dev, "hbm: stop response: message received\n");
+
+		dev->init_clients_timer = 0;
 
-		if (dev->hbm_state != MEI_HBM_STOP)
-			dev_err(&dev->pdev->dev, "unexpected stop response hbm.\n");
-		dev->dev_state = MEI_DEV_DISABLED;
-		dev_info(&dev->pdev->dev, "reset: FW stop response.\n");
-		mei_reset(dev, 1);
+		if (dev->hbm_state != MEI_HBM_STOPPED) {
+			dev_err(&dev->pdev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
+				dev->dev_state, dev->hbm_state);
+			return -EPROTO;
+		}
+
+		dev->dev_state = MEI_DEV_POWER_DOWN;
+		dev_info(&dev->pdev->dev, "hbm: stop response: resetting.\n");
+		/* force the reset */
+		return -EPROTO;
 		break;
 
 	case CLIENT_DISCONNECT_REQ_CMD:
-		/* search for client */
+		dev_dbg(&dev->pdev->dev, "hbm: disconnect request: message received\n");
+
 		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
 		mei_hbm_fw_disconnect_req(dev, disconnect_req);
 		break;
 
 	case ME_STOP_REQ_CMD:
-
-		dev->hbm_state = MEI_HBM_STOP;
-		mei_hbm_stop_req_prepare(dev, &dev->wr_ext_msg.hdr,
-					dev->wr_ext_msg.data);
+		dev_dbg(&dev->pdev->dev, "hbm: stop request: message received\n");
+		dev->hbm_state = MEI_HBM_STOPPED;
+		if (mei_hbm_stop_req(dev)) {
+			dev_err(&dev->pdev->dev, "hbm: start: failed to send stop request\n");
+			return -EIO;
+		}
 		break;
 	default:
 		BUG();
 		break;
 
 	}
+	return 0;
 }