1 files changed, 292 insertions, 302 deletions

diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index a9b81f5dacd..8e385a0ae60 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -31,10 +31,6 @@
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
 
-#include <linux/capability.h>
-#include <linux/slab.h>
-#include <linux/skbuff.h>
-
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
 #include <net/bluetooth/rfcomm.h>
@@ -44,57 +40,51 @@
 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
 #define RFCOMM_TTY_MINOR 0
 
+static DEFINE_MUTEX(rfcomm_ioctl_mutex);
 static struct tty_driver *rfcomm_tty_driver;
 
 struct rfcomm_dev {
+	struct tty_port		port;
 	struct list_head	list;
-	atomic_t		refcnt;
 
 	char			name[12];
 	int			id;
 	unsigned long		flags;
-	atomic_t		opened;
 	int			err;
 
+	unsigned long		status;		/* don't export to userspace */
+
 	bdaddr_t		src;
 	bdaddr_t		dst;
-	u8 			channel;
+	u8			channel;
 
-	uint 			modem_status;
+	uint			modem_status;
 
 	struct rfcomm_dlc	*dlc;
-	struct tty_struct	*tty;
-	wait_queue_head_t       wait;
-	struct tasklet_struct   wakeup_task;
 
 	struct device		*tty_dev;
 
-	atomic_t 		wmem_alloc;
+	atomic_t		wmem_alloc;
 
 	struct sk_buff_head	pending;
 };
 
 static LIST_HEAD(rfcomm_dev_list);
-static DEFINE_RWLOCK(rfcomm_dev_lock);
+static DEFINE_MUTEX(rfcomm_dev_lock);
 
 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
 
-static void rfcomm_tty_wakeup(unsigned long arg);
-
 /* ---- Device functions ---- */
-static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
+
+static void rfcomm_dev_destruct(struct tty_port *port)
 {
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
 	struct rfcomm_dlc *dlc = dev->dlc;
 
 	BT_DBG("dev %p dlc %p", dev, dlc);
 
-	/* Refcount should only hit zero when called from rfcomm_dev_del()
-	   which will have taken us off the list. Everything else are
-	   refcounting bugs. */
-	BUG_ON(!list_empty(&dev->list));
-
 	rfcomm_dlc_lock(dlc);
 	/* Detach DLC if it's owned by this dev */
 	if (dlc->owner == dev)
@@ -103,7 +93,12 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
 
 	rfcomm_dlc_put(dlc);
 
-	tty_unregister_device(rfcomm_tty_driver, dev->id);
+	if (dev->tty_dev)
+		tty_unregister_device(rfcomm_tty_driver, dev->id);
+
+	mutex_lock(&rfcomm_dev_lock);
+	list_del(&dev->list);
+	mutex_unlock(&rfcomm_dev_lock);
 
 	kfree(dev);
 
@@ -112,78 +107,101 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
 	module_put(THIS_MODULE);
 }
 
-static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
+/* device-specific initialization: open the dlc */
+static int rfcomm_dev_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+	int err;
+
+	err = rfcomm_dlc_open(dev->dlc, &dev->src, &dev->dst, dev->channel);
+	if (err)
+		set_bit(TTY_IO_ERROR, &tty->flags);
+	return err;
+}
+
+/* we block the open until the dlc->state becomes BT_CONNECTED */
+static int rfcomm_dev_carrier_raised(struct tty_port *port)
 {
-	atomic_inc(&dev->refcnt);
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+	return (dev->dlc->state == BT_CONNECTED);
 }
 
-static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
+/* device-specific cleanup: close the dlc */
+static void rfcomm_dev_shutdown(struct tty_port *port)
 {
-	/* The reason this isn't actually a race, as you no
-	   doubt have a little voice screaming at you in your
-	   head, is that the refcount should never actually
-	   reach zero unless the device has already been taken
-	   off the list, in rfcomm_dev_del(). And if that's not
-	   true, we'll hit the BUG() in rfcomm_dev_destruct()
-	   anyway. */
-	if (atomic_dec_and_test(&dev->refcnt))
-		rfcomm_dev_destruct(dev);
+	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+	if (dev->tty_dev->parent)
+		device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
+
+	/* close the dlc */
+	rfcomm_dlc_close(dev->dlc, 0);
 }
 
-static struct rfcomm_dev *__rfcomm_dev_get(int id)
+static const struct tty_port_operations rfcomm_port_ops = {
+	.destruct = rfcomm_dev_destruct,
+	.activate = rfcomm_dev_activate,
+	.shutdown = rfcomm_dev_shutdown,
+	.carrier_raised = rfcomm_dev_carrier_raised,
+};
+
+static struct rfcomm_dev *__rfcomm_dev_lookup(int id)
 {
 	struct rfcomm_dev *dev;
-	struct list_head  *p;
 
-	list_for_each(p, &rfcomm_dev_list) {
-		dev = list_entry(p, struct rfcomm_dev, list);
+	list_for_each_entry(dev, &rfcomm_dev_list, list)
 		if (dev->id == id)
 			return dev;
-	}
 
 	return NULL;
 }
 
-static inline struct rfcomm_dev *rfcomm_dev_get(int id)
+static struct rfcomm_dev *rfcomm_dev_get(int id)
 {
 	struct rfcomm_dev *dev;
 
-	read_lock(&rfcomm_dev_lock);
+	mutex_lock(&rfcomm_dev_lock);
 
-	dev = __rfcomm_dev_get(id);
+	dev = __rfcomm_dev_lookup(id);
 
-	if (dev) {
-		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
-			dev = NULL;
-		else
-			rfcomm_dev_hold(dev);
-	}
+	if (dev && !tty_port_get(&dev->port))
+		dev = NULL;
 
-	read_unlock(&rfcomm_dev_lock);
+	mutex_unlock(&rfcomm_dev_lock);
 
 	return dev;
 }
 
-static struct device *rfcomm_get_device(struct rfcomm_dev *dev)
+static void rfcomm_reparent_device(struct rfcomm_dev *dev)
 {
 	struct hci_dev *hdev;
 	struct hci_conn *conn;
 
 	hdev = hci_get_route(&dev->dst, &dev->src);
 	if (!hdev)
-		return NULL;
+		return;
 
+	/* The lookup results are unsafe to access without the
+	 * hci device lock (FIXME: why is this not documented?)
+	 */
+	hci_dev_lock(hdev);
 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &dev->dst);
 
-	hci_dev_put(hdev);
+	/* Just because the acl link is in the hash table is no
+	 * guarantee the sysfs device has been added ...
+	 */
+	if (conn && device_is_registered(&conn->dev))
+		device_move(dev->tty_dev, &conn->dev, DPM_ORDER_DEV_AFTER_PARENT);
 
-	return conn ? &conn->dev : NULL;
+	hci_dev_unlock(hdev);
+	hci_dev_put(hdev);
 }
 
 static ssize_t show_address(struct device *tty_dev, struct device_attribute *attr, char *buf)
 {
 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
-	return sprintf(buf, "%s\n", batostr(&dev->dst));
+	return sprintf(buf, "%pMR\n", &dev->dst);
 }
 
 static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
@@ -195,36 +213,33 @@ static ssize_t show_channel(struct device *tty_dev, struct device_attribute *att
 static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
 static DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
 
-static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
+static struct rfcomm_dev *__rfcomm_dev_add(struct rfcomm_dev_req *req,
+					   struct rfcomm_dlc *dlc)
 {
-	struct rfcomm_dev *dev;
-	struct list_head *head = &rfcomm_dev_list, *p;
+	struct rfcomm_dev *dev, *entry;
+	struct list_head *head = &rfcomm_dev_list;
 	int err = 0;
 
-	BT_DBG("id %d channel %d", req->dev_id, req->channel);
-
 	dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
 	if (!dev)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	write_lock_bh(&rfcomm_dev_lock);
+	mutex_lock(&rfcomm_dev_lock);
 
 	if (req->dev_id < 0) {
 		dev->id = 0;
 
-		list_for_each(p, &rfcomm_dev_list) {
-			if (list_entry(p, struct rfcomm_dev, list)->id != dev->id)
+		list_for_each_entry(entry, &rfcomm_dev_list, list) {
+			if (entry->id != dev->id)
 				break;
 
 			dev->id++;
-			head = p;
+			head = &entry->list;
 		}
 	} else {
 		dev->id = req->dev_id;
 
-		list_for_each(p, &rfcomm_dev_list) {
-			struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list);
-
+		list_for_each_entry(entry, &rfcomm_dev_list, list) {
 			if (entry->id == dev->id) {
 				err = -EADDRINUSE;
 				goto out;
@@ -233,7 +248,7 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 			if (entry->id > dev->id - 1)
 				break;
 
-			head = p;
+			head = &entry->list;
 		}
 	}
 
@@ -245,7 +260,6 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 	sprintf(dev->name, "rfcomm%d", dev->id);
 
 	list_add(&dev->list, head);
-	atomic_set(&dev->refcnt, 1);
 
 	bacpy(&dev->src, &req->src);
 	bacpy(&dev->dst, &req->dst);
@@ -254,10 +268,8 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 	dev->flags = req->flags &
 		((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
 
-	atomic_set(&dev->opened, 0);
-
-	init_waitqueue_head(&dev->wait);
-	tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev);
+	tty_port_init(&dev->port);
+	dev->port.ops = &rfcomm_port_ops;
 
 	skb_queue_head_init(&dev->pending);
 
@@ -293,20 +305,37 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 	   holds reference to this module. */
 	__module_get(THIS_MODULE);
 
+	mutex_unlock(&rfcomm_dev_lock);
+	return dev;
+
 out:
-	write_unlock_bh(&rfcomm_dev_lock);
+	mutex_unlock(&rfcomm_dev_lock);
+	kfree(dev);
+	return ERR_PTR(err);
+}
 
-	if (err < 0)
-		goto free;
+static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
+{
+	struct rfcomm_dev *dev;
+	struct device *tty;
 
-	dev->tty_dev = tty_register_device(rfcomm_tty_driver, dev->id, NULL);
+	BT_DBG("id %d channel %d", req->dev_id, req->channel);
+
+	dev = __rfcomm_dev_add(req, dlc);
+	if (IS_ERR(dev)) {
+		rfcomm_dlc_put(dlc);
+		return PTR_ERR(dev);
+	}
 
-	if (IS_ERR(dev->tty_dev)) {
-		err = PTR_ERR(dev->tty_dev);
-		list_del(&dev->list);
-		goto free;
+	tty = tty_port_register_device(&dev->port, rfcomm_tty_driver,
+			dev->id, NULL);
+	if (IS_ERR(tty)) {
+		tty_port_put(&dev->port);
+		return PTR_ERR(tty);
 	}
 
+	dev->tty_dev = tty;
+	rfcomm_reparent_device(dev);
 	dev_set_drvdata(dev->tty_dev, dev);
 
 	if (device_create_file(dev->tty_dev, &dev_attr_address) < 0)
@@ -316,70 +345,49 @@ out:
 		BT_ERR("Failed to create channel attribute");
 
 	return dev->id;
-
-free:
-	kfree(dev);
-	return err;
 }
 
-static void rfcomm_dev_del(struct rfcomm_dev *dev)
+/* ---- Send buffer ---- */
+static inline unsigned int rfcomm_room(struct rfcomm_dev *dev)
 {
-	BT_DBG("dev %p", dev);
-
-	BUG_ON(test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags));
-
-	if (atomic_read(&dev->opened) > 0)
-		return;
-
-	write_lock_bh(&rfcomm_dev_lock);
-	list_del_init(&dev->list);
-	write_unlock_bh(&rfcomm_dev_lock);
+	struct rfcomm_dlc *dlc = dev->dlc;
 
-	rfcomm_dev_put(dev);
-}
+	/* Limit the outstanding number of packets not yet sent to 40 */
+	int pending = 40 - atomic_read(&dev->wmem_alloc);
 
-/* ---- Send buffer ---- */
-static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
-{
-	/* We can't let it be zero, because we don't get a callback
-	   when tx_credits becomes nonzero, hence we'd never wake up */
-	return dlc->mtu * (dlc->tx_credits?:1);
+	return max(0, pending) * dlc->mtu;
 }
 
 static void rfcomm_wfree(struct sk_buff *skb)
 {
 	struct rfcomm_dev *dev = (void *) skb->sk;
-	atomic_sub(skb->truesize, &dev->wmem_alloc);
+	atomic_dec(&dev->wmem_alloc);
 	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
-		tasklet_schedule(&dev->wakeup_task);
-	rfcomm_dev_put(dev);
+		tty_port_tty_wakeup(&dev->port);
+	tty_port_put(&dev->port);
 }
 
-static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
+static void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
 {
-	rfcomm_dev_hold(dev);
-	atomic_add(skb->truesize, &dev->wmem_alloc);
+	tty_port_get(&dev->port);
+	atomic_inc(&dev->wmem_alloc);
 	skb->sk = (void *) dev;
 	skb->destructor = rfcomm_wfree;
 }
 
 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
 {
-	if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
-		struct sk_buff *skb = alloc_skb(size, priority);
-		if (skb) {
-			rfcomm_set_owner_w(skb, dev);
-			return skb;
-		}
-	}
-	return NULL;
+	struct sk_buff *skb = alloc_skb(size, priority);
+	if (skb)
+		rfcomm_set_owner_w(skb, dev);
+	return skb;
 }
 
 /* ---- Device IOCTLs ---- */
 
 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
 
-static int rfcomm_create_dev(struct sock *sk, void __user *arg)
+static int __rfcomm_create_dev(struct sock *sk, void __user *arg)
 {
 	struct rfcomm_dev_req req;
 	struct rfcomm_dlc *dlc;
@@ -401,16 +409,22 @@ static int rfcomm_create_dev(struct sock *sk, void __user *arg)
 		dlc = rfcomm_pi(sk)->dlc;
 		rfcomm_dlc_hold(dlc);
 	} else {
+		/* Validate the channel is unused */
+		dlc = rfcomm_dlc_exists(&req.src, &req.dst, req.channel);
+		if (IS_ERR(dlc))
+			return PTR_ERR(dlc);
+		else if (dlc) {
+			rfcomm_dlc_put(dlc);
+			return -EBUSY;
+		}
 		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
 		if (!dlc)
 			return -ENOMEM;
 	}
 
 	id = rfcomm_dev_add(&req, dlc);
-	if (id < 0) {
-		rfcomm_dlc_put(dlc);
+	if (id < 0)
 		return id;
-	}
 
 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
 		/* DLC is now used by device.
@@ -421,42 +435,76 @@ static int rfcomm_create_dev(struct sock *sk, void __user *arg)
 	return id;
 }
 
-static int rfcomm_release_dev(void __user *arg)
+static int __rfcomm_release_dev(void __user *arg)
 {
 	struct rfcomm_dev_req req;
 	struct rfcomm_dev *dev;
+	struct tty_struct *tty;
 
 	if (copy_from_user(&req, arg, sizeof(req)))
 		return -EFAULT;
 
 	BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
 
-	if (!(dev = rfcomm_dev_get(req.dev_id)))
+	dev = rfcomm_dev_get(req.dev_id);
+	if (!dev)
 		return -ENODEV;
 
 	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
-		rfcomm_dev_put(dev);
+		tty_port_put(&dev->port);
 		return -EPERM;
 	}
 
+	/* only release once */
+	if (test_and_set_bit(RFCOMM_DEV_RELEASED, &dev->status)) {
+		tty_port_put(&dev->port);
+		return -EALREADY;
+	}
+
 	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
 		rfcomm_dlc_close(dev->dlc, 0);
 
 	/* Shut down TTY synchronously before freeing rfcomm_dev */
-	if (dev->tty)
-		tty_vhangup(dev->tty);
+	tty = tty_port_tty_get(&dev->port);
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+
+	if (!test_bit(RFCOMM_TTY_OWNED, &dev->status))
+		tty_port_put(&dev->port);
 
-	if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
-		rfcomm_dev_del(dev);
-	rfcomm_dev_put(dev);
+	tty_port_put(&dev->port);
 	return 0;
 }
 
+static int rfcomm_create_dev(struct sock *sk, void __user *arg)
+{
+	int ret;
+
+	mutex_lock(&rfcomm_ioctl_mutex);
+	ret = __rfcomm_create_dev(sk, arg);
+	mutex_unlock(&rfcomm_ioctl_mutex);
+
+	return ret;
+}
+
+static int rfcomm_release_dev(void __user *arg)
+{
+	int ret;
+
+	mutex_lock(&rfcomm_ioctl_mutex);
+	ret = __rfcomm_release_dev(arg);
+	mutex_unlock(&rfcomm_ioctl_mutex);
+
+	return ret;
+}
+
 static int rfcomm_get_dev_list(void __user *arg)
 {
+	struct rfcomm_dev *dev;
 	struct rfcomm_dev_list_req *dl;
 	struct rfcomm_dev_info *di;
-	struct list_head *p;
 	int n = 0, size, err;
 	u16 dev_num;
 
@@ -470,16 +518,16 @@ static int rfcomm_get_dev_list(void __user *arg)
 
 	size = sizeof(*dl) + dev_num * sizeof(*di);
 
-	if (!(dl = kmalloc(size, GFP_KERNEL)))
+	dl = kzalloc(size, GFP_KERNEL);
+	if (!dl)
 		return -ENOMEM;
 
 	di = dl->dev_info;
 
-	read_lock_bh(&rfcomm_dev_lock);
+	mutex_lock(&rfcomm_dev_lock);
 
-	list_for_each(p, &rfcomm_dev_list) {
-		struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list);
-		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
+	list_for_each_entry(dev, &rfcomm_dev_list, list) {
+		if (!tty_port_get(&dev->port))
 			continue;
 		(di + n)->id      = dev->id;
 		(di + n)->flags   = dev->flags;
@@ -487,11 +535,12 @@ static int rfcomm_get_dev_list(void __user *arg)
 		(di + n)->channel = dev->channel;
 		bacpy(&(di + n)->src, &dev->src);
 		bacpy(&(di + n)->dst, &dev->dst);
+		tty_port_put(&dev->port);
 		if (++n >= dev_num)
 			break;
 	}
 
-	read_unlock_bh(&rfcomm_dev_lock);
+	mutex_unlock(&rfcomm_dev_lock);
 
 	dl->dev_num = n;
 	size = sizeof(*dl) + n * sizeof(*di);
@@ -513,7 +562,8 @@ static int rfcomm_get_dev_info(void __user *arg)
 	if (copy_from_user(&di, arg, sizeof(di)))
 		return -EFAULT;
 
-	if (!(dev = rfcomm_dev_get(di.id)))
+	dev = rfcomm_dev_get(di.id);
+	if (!dev)
 		return -ENODEV;
 
 	di.flags   = dev->flags;
@@ -525,7 +575,7 @@ static int rfcomm_get_dev_info(void __user *arg)
 	if (copy_to_user(arg, &di, sizeof(di)))
 		err = -EFAULT;
 
-	rfcomm_dev_put(dev);
+	tty_port_put(&dev->port);
 	return err;
 }
 
@@ -554,22 +604,21 @@ int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
 {
 	struct rfcomm_dev *dev = dlc->owner;
-	struct tty_struct *tty;
 
 	if (!dev) {
 		kfree_skb(skb);
 		return;
 	}
 
-	if (!(tty = dev->tty) || !skb_queue_empty(&dev->pending)) {
+	if (!skb_queue_empty(&dev->pending)) {
 		skb_queue_tail(&dev->pending, skb);
 		return;
 	}
 
-	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
+	BT_DBG("dlc %p len %d", dlc, skb->len);
 
-	tty_insert_flip_string(tty, skb->data, skb->len);
-	tty_flip_buffer_push(tty);
+	tty_insert_flip_string(&dev->port, skb->data, skb->len);
+	tty_flip_buffer_push(&dev->port);
 
 	kfree_skb(skb);
 }
@@ -583,31 +632,12 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
 	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
 
 	dev->err = err;
-	wake_up_interruptible(&dev->wait);
-
-	if (dlc->state == BT_CLOSED) {
-		if (!dev->tty) {
-			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
-				/* Drop DLC lock here to avoid deadlock
-				 * 1. rfcomm_dev_get will take rfcomm_dev_lock
-				 *    but in rfcomm_dev_add there's lock order:
-				 *    rfcomm_dev_lock -> dlc lock
-				 * 2. rfcomm_dev_put will deadlock if it's
-				 *    the last reference
-				 */
-				rfcomm_dlc_unlock(dlc);
-				if (rfcomm_dev_get(dev->id) == NULL) {
-					rfcomm_dlc_lock(dlc);
-					return;
-				}
-
-				rfcomm_dev_del(dev);
-				rfcomm_dev_put(dev);
-				rfcomm_dlc_lock(dlc);
-			}
-		} else
-			tty_hangup(dev->tty);
-	}
+	if (dlc->state == BT_CONNECTED) {
+		rfcomm_reparent_device(dev);
+
+		wake_up_interruptible(&dev->port.open_wait);
+	} else if (dlc->state == BT_CLOSED)
+		tty_port_tty_hangup(&dev->port, false);
 }
 
 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
@@ -618,10 +648,8 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
 
 	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
 
-	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV)) {
-		if (dev->tty && !C_CLOCAL(dev->tty))
-			tty_hangup(dev->tty);
-	}
+	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV))
+		tty_port_tty_hangup(&dev->port, true);
 
 	dev->modem_status =
 		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
@@ -631,148 +659,125 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
 }
 
 /* ---- TTY functions ---- */
-static void rfcomm_tty_wakeup(unsigned long arg)
-{
-	struct rfcomm_dev *dev = (void *) arg;
-	struct tty_struct *tty = dev->tty;
-	if (!tty)
-		return;
-
-	BT_DBG("dev %p tty %p", dev, tty);
-	tty_wakeup(tty);
-}
-
 static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
 {
-	struct tty_struct *tty = dev->tty;
 	struct sk_buff *skb;
 	int inserted = 0;
 
-	if (!tty)
-		return;
-
-	BT_DBG("dev %p tty %p", dev, tty);
+	BT_DBG("dev %p", dev);
 
 	rfcomm_dlc_lock(dev->dlc);
 
 	while ((skb = skb_dequeue(&dev->pending))) {
-		inserted += tty_insert_flip_string(tty, skb->data, skb->len);
+		inserted += tty_insert_flip_string(&dev->port, skb->data,
+				skb->len);
 		kfree_skb(skb);
 	}
 
 	rfcomm_dlc_unlock(dev->dlc);
 
 	if (inserted > 0)
-		tty_flip_buffer_push(tty);
+		tty_flip_buffer_push(&dev->port);
 }
 
-static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+/* do the reverse of install, clearing the tty fields and releasing the
+ * reference to tty_port
+ */
+static void rfcomm_tty_cleanup(struct tty_struct *tty)
 {
-	DECLARE_WAITQUEUE(wait, current);
-	struct rfcomm_dev *dev;
-	struct rfcomm_dlc *dlc;
-	int err, id;
+	struct rfcomm_dev *dev = tty->driver_data;
 
-	id = tty->index;
+	clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 
-	BT_DBG("tty %p id %d", tty, id);
+	rfcomm_dlc_lock(dev->dlc);
+	tty->driver_data = NULL;
+	rfcomm_dlc_unlock(dev->dlc);
 
-	/* We don't leak this refcount. For reasons which are not entirely
-	   clear, the TTY layer will call our ->close() method even if the
-	   open fails. We decrease the refcount there, and decreasing it
-	   here too would cause breakage. */
-	dev = rfcomm_dev_get(id);
-	if (!dev)
-		return -ENODEV;
+	/*
+	 * purge the dlc->tx_queue to avoid circular dependencies
+	 * between dev and dlc
+	 */
+	skb_queue_purge(&dev->dlc->tx_queue);
 
-	BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst),
-				dev->channel, atomic_read(&dev->opened));
+	tty_port_put(&dev->port);
+}
 
-	if (atomic_inc_return(&dev->opened) > 1)
-		return 0;
+/* we acquire the tty_port reference since it's here the tty is first used
+ * by setting the termios. We also populate the driver_data field and install
+ * the tty port
+ */
+static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct rfcomm_dev *dev;
+	struct rfcomm_dlc *dlc;
+	int err;
+
+	dev = rfcomm_dev_get(tty->index);
+	if (!dev)
+		return -ENODEV;
 
 	dlc = dev->dlc;
 
 	/* Attach TTY and open DLC */
-
 	rfcomm_dlc_lock(dlc);
 	tty->driver_data = dev;
-	dev->tty = tty;
 	rfcomm_dlc_unlock(dlc);
 	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 
-	err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
-	if (err < 0)
+	/* install the tty_port */
+	err = tty_port_install(&dev->port, driver, tty);
+	if (err) {
+		rfcomm_tty_cleanup(tty);
 		return err;
+	}
 
-	/* Wait for DLC to connect */
-	add_wait_queue(&dev->wait, &wait);
-	while (1) {
-		set_current_state(TASK_INTERRUPTIBLE);
+	/* take over the tty_port reference if the port was created with the
+	 * flag RFCOMM_RELEASE_ONHUP. This will force the release of the port
+	 * when the last process closes the tty. The behaviour is expected by
+	 * userspace.
+	 */
+	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
+		set_bit(RFCOMM_TTY_OWNED, &dev->status);
+		tty_port_put(&dev->port);
+	}
 
-		if (dlc->state == BT_CLOSED) {
-			err = -dev->err;
-			break;
-		}
+	return 0;
+}
 
-		if (dlc->state == BT_CONNECTED)
-			break;
+static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct rfcomm_dev *dev = tty->driver_data;
+	int err;
 
-		if (signal_pending(current)) {
-			err = -EINTR;
-			break;
-		}
+	BT_DBG("tty %p id %d", tty, tty->index);
 
-		schedule();
-	}
-	set_current_state(TASK_RUNNING);
-	remove_wait_queue(&dev->wait, &wait);
+	BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
+	       dev->channel, dev->port.count);
 
-	if (err == 0)
-		device_move(dev->tty_dev, rfcomm_get_device(dev),
-			    DPM_ORDER_DEV_AFTER_PARENT);
+	err = tty_port_open(&dev->port, tty, filp);
+	if (err)
+		return err;
 
+	/*
+	 * FIXME: rfcomm should use proper flow control for
+	 * received data. This hack will be unnecessary and can
+	 * be removed when that's implemented
+	 */
 	rfcomm_tty_copy_pending(dev);
 
 	rfcomm_dlc_unthrottle(dev->dlc);
 
-	return err;
+	return 0;
 }
 
 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 {
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
-	if (!dev)
-		return;
 
 	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
-						atomic_read(&dev->opened));
-
-	if (atomic_dec_and_test(&dev->opened)) {
-		if (dev->tty_dev->parent)
-			device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
-
-		/* Close DLC and dettach TTY */
-		rfcomm_dlc_close(dev->dlc, 0);
-
-		clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
-		tasklet_kill(&dev->wakeup_task);
-
-		rfcomm_dlc_lock(dev->dlc);
-		tty->driver_data = NULL;
-		dev->tty = NULL;
-		rfcomm_dlc_unlock(dev->dlc);
-
-		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) {
-			write_lock_bh(&rfcomm_dev_lock);
-			list_del_init(&dev->list);
-			write_unlock_bh(&rfcomm_dev_lock);
+						dev->port.count);
 
-			rfcomm_dev_put(dev);
-		}
-	}
-
-	rfcomm_dev_put(dev);
+	tty_port_close(&dev->port, tty, filp);
 }
 
 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -780,7 +785,7 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 	struct rfcomm_dlc *dlc = dev->dlc;
 	struct sk_buff *skb;
-	int err = 0, sent = 0, size;
+	int sent = 0, size;
 
 	BT_DBG("tty %p count %d", tty, count);
 
@@ -788,7 +793,6 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
 		size = min_t(uint, count, dlc->mtu);
 
 		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
-
 		if (!skb)
 			break;
 
@@ -796,36 +800,29 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
 
 		memcpy(skb_put(skb, size), buf + sent, size);
 
-		if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
-			kfree_skb(skb);
-			break;
-		}
+		rfcomm_dlc_send_noerror(dlc, skb);
 
 		sent  += size;
 		count -= size;
 	}
 
-	return sent ? sent : err;
+	return sent;
 }
 
 static int rfcomm_tty_write_room(struct tty_struct *tty)
 {
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
-	int room;
+	int room = 0;
 
-	BT_DBG("tty %p", tty);
+	if (dev && dev->dlc)
+		room = rfcomm_room(dev);
 
-	if (!dev || !dev->dlc)
-		return 0;
-
-	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
-	if (room < 0)
-		room = 0;
+	BT_DBG("tty %p room %d", tty, room);
 
 	return room;
 }
 
-static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
+static int rfcomm_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 {
 	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
 
@@ -872,7 +869,7 @@ static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned
 
 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 {
-	struct ktermios *new = tty->termios;
+	struct ktermios *new = &tty->termios;
 	int old_baud_rate = tty_termios_baud_rate(old);
 	int new_baud_rate = tty_termios_baud_rate(new);
 
@@ -892,7 +889,7 @@ static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 
 	/* Parity on/off and when on, odd/even */
 	if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
-			((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
+			((old->c_cflag & PARODD) != (new->c_cflag & PARODD))) {
 		changes |= RFCOMM_RPN_PM_PARITY;
 		BT_DBG("Parity change detected.");
 	}
@@ -937,11 +934,10 @@ static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 	/* POSIX does not support 1.5 stop bits and RFCOMM does not
 	 * support 2 stop bits. So a request for 2 stop bits gets
 	 * translated to 1.5 stop bits */
-	if (new->c_cflag & CSTOPB) {
+	if (new->c_cflag & CSTOPB)
 		stop_bits = RFCOMM_RPN_STOP_15;
-	} else {
+	else
 		stop_bits = RFCOMM_RPN_STOP_1;
-	}
 
 	/* Handle number of data bits [5-8] */
 	if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
@@ -1072,20 +1068,10 @@ static void rfcomm_tty_hangup(struct tty_struct *tty)
 
 	BT_DBG("tty %p dev %p", tty, dev);
 
-	if (!dev)
-		return;
-
-	rfcomm_tty_flush_buffer(tty);
-
-	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
-		if (rfcomm_dev_get(dev->id) == NULL)
-			return;
-		rfcomm_dev_del(dev);
-		rfcomm_dev_put(dev);
-	}
+	tty_port_hangup(&dev->port);
 }
 
-static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
+static int rfcomm_tty_tiocmget(struct tty_struct *tty)
 {
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 
@@ -1094,7 +1080,7 @@ static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
 	return dev->modem_status;
 }
 
-static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
+static int rfcomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
 {
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 	struct rfcomm_dlc *dlc = dev->dlc;
@@ -1145,15 +1131,18 @@ static const struct tty_operations rfcomm_ops = {
 	.wait_until_sent	= rfcomm_tty_wait_until_sent,
 	.tiocmget		= rfcomm_tty_tiocmget,
 	.tiocmset		= rfcomm_tty_tiocmset,
+	.install                = rfcomm_tty_install,
+	.cleanup                = rfcomm_tty_cleanup,
 };
 
 int __init rfcomm_init_ttys(void)
 {
+	int error;
+
 	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
 	if (!rfcomm_tty_driver)
-		return -1;
+		return -ENOMEM;
 
-	rfcomm_tty_driver->owner	= THIS_MODULE;
 	rfcomm_tty_driver->driver_name	= "rfcomm";
 	rfcomm_tty_driver->name		= "rfcomm";
 	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
@@ -1162,14 +1151,15 @@ int __init rfcomm_init_ttys(void)
 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
 	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 	rfcomm_tty_driver->init_termios	= tty_std_termios;
-	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL;
 	rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
 
-	if (tty_register_driver(rfcomm_tty_driver)) {
+	error = tty_register_driver(rfcomm_tty_driver);
+	if (error) {
 		BT_ERR("Can't register RFCOMM TTY driver");
 		put_tty_driver(rfcomm_tty_driver);
-		return -1;
+		return error;
 	}
 
 	BT_INFO("RFCOMM TTY layer initialized");