mei: revamp client disconnection flow

Split disconnected state into two parts first reception disconnect
response from the firmware and second actually setting of disconnected
state.  Book keeping data are needed for processing and after firmware
disconnected the client and are cleaned when setting the disconnected
state in mei_cl_set_disconneted() function.
Add mei_cl_send_disconnect to reduce code duplication.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus.c

@@ -480,8 +480,6 @@ int mei_cl_disable_device(struct mei_cl_device *device)
 		goto out;
 	}
 
-	cl->state = MEI_FILE_DISCONNECTING;
-
 	err = mei_cl_disconnect(cl);
 	if (err < 0) {
 		dev_err(dev->dev, "Could not disconnect from the ME client");

drivers/misc/mei/client.c

@@ -546,6 +546,7 @@ void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 	INIT_LIST_HEAD(&cl->link);
 	INIT_LIST_HEAD(&cl->device_link);
 	cl->writing_state = MEI_IDLE;
+	cl->state = MEI_FILE_INITIALIZING;
 	cl->dev = dev;
 }
 
@@ -714,6 +715,88 @@ bool mei_hbuf_acquire(struct mei_device *dev)
 	return true;
 }
 
+/**
+ * mei_cl_set_disconnected - set disconnected state and clear
+ *   associated states and resources
+ *
+ * @cl: host client
+ */
+void mei_cl_set_disconnected(struct mei_cl *cl)
+{
+	struct mei_device *dev = cl->dev;
+
+	if (cl->state == MEI_FILE_DISCONNECTED ||
+	    cl->state == MEI_FILE_INITIALIZING)
+		return;
+
+	cl->state = MEI_FILE_DISCONNECTED;
+	mei_io_list_flush(&dev->ctrl_rd_list, cl);
+	mei_io_list_flush(&dev->ctrl_wr_list, cl);
+	cl->mei_flow_ctrl_creds = 0;
+	cl->timer_count = 0;
+}
+
+/*
+ * mei_cl_send_disconnect - send disconnect request
+ *
+ * @cl: host client
+ * @cb: callback block
+ *
+ * Return: 0, OK; otherwise, error.
+ */
+static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
+{
+	struct mei_device *dev;
+	int ret;
+
+	dev = cl->dev;
+
+	ret = mei_hbm_cl_disconnect_req(dev, cl);
+	cl->status = ret;
+	if (ret) {
+		cl->state = MEI_FILE_DISCONNECT_REPLY;
+		return ret;
+	}
+
+	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
+	cl->timer_count = MEI_CONNECT_TIMEOUT;
+
+	return 0;
+}
+
+/**
+ * mei_cl_irq_disconnect - processes close related operation from
+ *	interrupt thread context - send disconnect request
+ *
+ * @cl: client
+ * @cb: callback block.
+ * @cmpl_list: complete list.
+ *
+ * Return: 0, OK; otherwise, error.
+ */
+int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
+			    struct mei_cl_cb *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
+
+	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
+	slots = mei_hbuf_empty_slots(dev);
+
+	if (slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_cl_send_disconnect(cl, cb);
+	if (ret)
+		list_move_tail(&cb->list, &cmpl_list->list);
+
+	return ret;
+}
+
+
+
 /**
  * mei_cl_disconnect - disconnect host client from the me one
  *
@@ -736,7 +819,7 @@ int mei_cl_disconnect(struct mei_cl *cl)
 
 	cl_dbg(dev, cl, "disconnecting");
 
-	if (cl->state != MEI_FILE_DISCONNECTING)
+	if (!mei_cl_is_connected(cl))
 		return 0;
 
 	rets = pm_runtime_get(dev->dev);
@@ -746,44 +829,41 @@ int mei_cl_disconnect(struct mei_cl *cl)
 		return rets;
 	}
 
+	cl->state = MEI_FILE_DISCONNECTING;
+
 	cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT, NULL);
 	rets = cb ? 0 : -ENOMEM;
 	if (rets)
-		goto free;
+		goto out;
 
-	if (mei_hbuf_acquire(dev)) {
-		if (mei_hbm_cl_disconnect_req(dev, cl)) {
-			rets = -ENODEV;
-			cl_err(dev, cl, "failed to disconnect.\n");
-			goto free;
-		}
-		cl->timer_count = MEI_CONNECT_TIMEOUT;
-		mdelay(10); /* Wait for hardware disconnection ready */
-		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
-	} else {
 	cl_dbg(dev, cl, "add disconnect cb to control write list\n");
 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 
+	if (mei_hbuf_acquire(dev)) {
+		rets = mei_cl_send_disconnect(cl, cb);
+		if (rets) {
+			cl_err(dev, cl, "failed to disconnect.\n");
+			goto out;
+		}
 	}
-	mutex_unlock(&dev->device_lock);
 
-	wait_event_timeout(cl->wait,
-			MEI_FILE_DISCONNECTED == cl->state,
+	mutex_unlock(&dev->device_lock);
+	wait_event_timeout(cl->wait, cl->state == MEI_FILE_DISCONNECT_REPLY,
 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
-
 	mutex_lock(&dev->device_lock);
 
-	if (MEI_FILE_DISCONNECTED == cl->state) {
-		rets = 0;
-		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
-	} else {
+	rets = cl->status;
+	if (cl->state != MEI_FILE_DISCONNECT_REPLY) {
 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
 		rets = -ETIME;
 	}
 
-	mei_io_list_flush(&dev->ctrl_rd_list, cl);
-	mei_io_list_flush(&dev->ctrl_wr_list, cl);
-free:
+out:
+	/* we disconnect also on error */
+	mei_cl_set_disconnected(cl);
+	if (!rets)
+		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
+
 	cl_dbg(dev, cl, "rpm: autosuspend\n");
 	pm_runtime_mark_last_busy(dev->dev);
 	pm_runtime_put_autosuspend(dev->dev);
@@ -872,18 +952,15 @@ int mei_cl_connect(struct mei_cl *cl, struct file *file)
 	mutex_unlock(&dev->device_lock);
 	wait_event_timeout(cl->wait,
 			(cl->state == MEI_FILE_CONNECTED ||
-			 cl->state == MEI_FILE_DISCONNECTED),
+			 cl->state == MEI_FILE_DISCONNECT_REPLY),
 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
 	if (!mei_cl_is_connected(cl)) {
-		cl->state = MEI_FILE_DISCONNECTED;
 		/* something went really wrong */
 		if (!cl->status)
 			cl->status = -EFAULT;
-
-		mei_io_list_flush(&dev->ctrl_rd_list, cl);
-		mei_io_list_flush(&dev->ctrl_wr_list, cl);
+		mei_cl_set_disconnected(cl);
 	}
 
 	rets = cl->status;
@@ -1289,20 +1366,30 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
  */
 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 {
-	if (cb->fop_type == MEI_FOP_WRITE) {
+	switch (cb->fop_type) {
+	case MEI_FOP_WRITE:
 		mei_io_cb_free(cb);
-		cb = NULL;
 		cl->writing_state = MEI_WRITE_COMPLETE;
 		if (waitqueue_active(&cl->tx_wait))
 			wake_up_interruptible(&cl->tx_wait);
+		break;
 
-	} else if (cb->fop_type == MEI_FOP_READ) {
+	case MEI_FOP_READ:
 		list_add_tail(&cb->list, &cl->rd_completed);
 		if (waitqueue_active(&cl->rx_wait))
 			wake_up_interruptible_all(&cl->rx_wait);
 		else
 			mei_cl_bus_rx_event(cl);
+		break;
+
+	case MEI_FOP_CONNECT:
+	case MEI_FOP_DISCONNECT:
+		if (waitqueue_active(&cl->wait))
+			wake_up(&cl->wait);
 
+		break;
+	default:
+		BUG_ON(0);
 	}
 }
 
@@ -1312,16 +1399,12 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
  *
  * @dev: mei device
  */
-
 void mei_cl_all_disconnect(struct mei_device *dev)
 {
 	struct mei_cl *cl;
 
-	list_for_each_entry(cl, &dev->file_list, link) {
-		cl->state = MEI_FILE_DISCONNECTED;
-		cl->mei_flow_ctrl_creds = 0;
-		cl->timer_count = 0;
-	}
+	list_for_each_entry(cl, &dev->file_list, link)
+		mei_cl_set_disconnected(cl);
 }
 
 

drivers/misc/mei/client.h

@@ -105,6 +105,9 @@ static inline bool mei_cl_is_connected(struct mei_cl *cl)
 
 bool mei_cl_is_other_connecting(struct mei_cl *cl);
 int mei_cl_disconnect(struct mei_cl *cl);
+void mei_cl_set_disconnected(struct mei_cl *cl);
+int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
+			  struct mei_cl_cb *cmpl_list);
 int mei_cl_connect(struct mei_cl *cl, struct file *file);
 int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp);
 int mei_cl_irq_read_msg(struct mei_cl *cl, struct mei_msg_hdr *hdr,

drivers/misc/mei/hbm.c

@@ -572,7 +572,7 @@ static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
 	cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);
 
 	if (rs->status == MEI_CL_DISCONN_SUCCESS)
-		cl->state = MEI_FILE_DISCONNECTED;
+		cl->state = MEI_FILE_DISCONNECT_REPLY;
 	cl->status = 0;
 }
 
@@ -611,7 +611,7 @@ static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
 	if (rs->status == MEI_CL_CONN_SUCCESS)
 		cl->state = MEI_FILE_CONNECTED;
 	else
-		cl->state = MEI_FILE_DISCONNECTED;
+		cl->state = MEI_FILE_DISCONNECT_REPLY;
 	cl->status = mei_cl_conn_status_to_errno(rs->status);
 }
 
@@ -680,8 +680,8 @@ static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
 
 	cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
 	if (cl) {
-		cl_dbg(dev, cl, "disconnect request received\n");
-		cl->state = MEI_FILE_DISCONNECTED;
+		cl_dbg(dev, cl, "fw disconnect request received\n");
+		cl->state = MEI_FILE_DISCONNECTING;
 		cl->timer_count = 0;
 
 		cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL);

drivers/misc/mei/interrupt.c

@@ -180,56 +180,12 @@ static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
 		return -EMSGSIZE;
 
 	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
-
-	cl->state = MEI_FILE_DISCONNECTED;
-	cl->status = 0;
+	mei_cl_set_disconnected(cl);
 	mei_io_cb_free(cb);
 
 	return ret;
 }
 
-
-
-/**
- * mei_cl_irq_disconnect - processes close related operation from
- *	interrupt thread context - send disconnect request
- *
- * @cl: client
- * @cb: callback block.
- * @cmpl_list: complete list.
- *
- * Return: 0, OK; otherwise, error.
- */
-static int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
-			    struct mei_cl_cb *cmpl_list)
-{
-	struct mei_device *dev = cl->dev;
-	u32 msg_slots;
-	int slots;
-
-	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
-	slots = mei_hbuf_empty_slots(dev);
-
-	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;
-	}
-
-	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_cl_irq_read - processes client read related operation from the
  *	interrupt thread context - request for flow control credits

drivers/misc/mei/main.c

@@ -94,7 +94,7 @@ static int mei_release(struct inode *inode, struct file *file)
 {
 	struct mei_cl *cl = file->private_data;
 	struct mei_device *dev;
-	int rets = 0;
+	int rets;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
@@ -106,11 +106,8 @@ static int mei_release(struct inode *inode, struct file *file)
 		rets = mei_amthif_release(dev, file);
 		goto out;
 	}
-	if (mei_cl_is_connected(cl)) {
-		cl->state = MEI_FILE_DISCONNECTING;
-		cl_dbg(dev, cl, "disconnecting\n");
 	rets = mei_cl_disconnect(cl);
-	}
+
 	mei_cl_flush_queues(cl, file);
 	cl_dbg(dev, cl, "removing\n");
 

drivers/misc/mei/mei_dev.h

@@ -88,7 +88,8 @@ enum file_state {
 	MEI_FILE_CONNECTING,
 	MEI_FILE_CONNECTED,
 	MEI_FILE_DISCONNECTING,
-	MEI_FILE_DISCONNECTED
+	MEI_FILE_DISCONNECT_REPLY,
+	MEI_FILE_DISCONNECTED,
 };
 
 /* MEI device states */