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 <[e-mail]>
Signed-off-by: Alexander Usyskin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/mei/bus.c

···
 		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

···
 	INIT_LIST_HEAD(&cl->link);
 	INIT_LIST_HEAD(&cl->device_link);
 	cl->writing_state = MEI_IDLE;
+	cl->state = MEI_FILE_INITIALIZING;
 	cl->dev = dev;
 }
 
···
 }
 
 /**
+ * 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
  *
  * @cl: host client
···
 
 	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);
···
 		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;
+
+	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)) {
-		if (mei_hbm_cl_disconnect_req(dev, cl)) {
-			rets = -ENODEV;
+		rets = mei_cl_send_disconnect(cl, cb);
+		if (rets) {
 			cl_err(dev, cl, "failed to disconnect.\n");
-			goto free;
+			goto out;
 		}
-		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);
-
 	}
+
 	mutex_unlock(&dev->device_lock);
-
-	wait_event_timeout(cl->wait,
-			MEI_FILE_DISCONNECTED == cl->state,
-			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
-
+	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);
···
 	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;
···
  */
 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);
 	}
 }
 
···
  *
  * @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

···
 
 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

···
 	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;
 }
 
···
 	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);
 }
 
···
 
 	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

···
 		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

drivers/misc/mei/main.c

···
 {
 	struct mei_cl *cl = file->private_data;
 	struct mei_device *dev;
-	int rets = 0;
+	int rets;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
···
 		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);
-	}
+	rets = mei_cl_disconnect(cl);
+
 	mei_cl_flush_queues(cl, file);
 	cl_dbg(dev, cl, "removing\n");
 

drivers/misc/mei/mei_dev.h

···
 	MEI_FILE_CONNECTING,
 	MEI_FILE_CONNECTED,
 	MEI_FILE_DISCONNECTING,
-	MEI_FILE_DISCONNECTED
+	MEI_FILE_DISCONNECT_REPLY,
+	MEI_FILE_DISCONNECTED,
 };
 
 /* MEI device states */