2 files changed, 189 insertions, 138 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index e8c564a53346..3027ada1b812 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -58,12 +58,64 @@ static struct usb_driver acm_driver;
 static struct tty_driver *acm_tty_driver;
 static struct acm *acm_table[ACM_TTY_MINORS];
 
-static DEFINE_MUTEX(open_mutex);
+static DEFINE_MUTEX(acm_table_lock);
 
 #define ACM_READY(acm)	(acm && acm->dev && acm->port.count)
 
-static const struct tty_port_operations acm_port_ops = {
-};
+/*
+ * acm_table accessors
+ */
+
+/*
+ * Look up an ACM structure by index. If found and not disconnected, increment
+ * its refcount and return it with its mutex held.
+ */
+static struct acm *acm_get_by_index(unsigned index)
+{
+	struct acm *acm;
+
+	mutex_lock(&acm_table_lock);
+	acm = acm_table[index];
+	if (acm) {
+		mutex_lock(&acm->mutex);
+		if (acm->disconnected) {
+			mutex_unlock(&acm->mutex);
+			acm = NULL;
+		} else {
+			tty_port_get(&acm->port);
+			mutex_unlock(&acm->mutex);
+		}
+	}
+	mutex_unlock(&acm_table_lock);
+	return acm;
+}
+
+/*
+ * Try to find an available minor number and if found, associate it with 'acm'.
+ */
+static int acm_alloc_minor(struct acm *acm)
+{
+	int minor;
+
+	mutex_lock(&acm_table_lock);
+	for (minor = 0; minor < ACM_TTY_MINORS; minor++) {
+		if (!acm_table[minor]) {
+			acm_table[minor] = acm;
+			break;
+		}
+	}
+	mutex_unlock(&acm_table_lock);
+
+	return minor;
+}
+
+/* Release the minor number associated with 'acm'.  */
+static void acm_release_minor(struct acm *acm)
+{
+	mutex_lock(&acm_table_lock);
+	acm_table[acm->minor] = NULL;
+	mutex_unlock(&acm_table_lock);
+}
 
 /*
  * Functions for ACM control messages.
@@ -453,93 +505,122 @@ static void acm_softint(struct work_struct *work)
  * TTY handlers
  */
 
-static int acm_tty_open(struct tty_struct *tty, struct file *filp)
+static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	struct acm *acm;
-	int rv = -ENODEV;
-
-	mutex_lock(&open_mutex);
+	int retval;
 
-	acm = acm_table[tty->index];
-	if (!acm || !acm->dev)
-		goto out;
-	else
-		rv = 0;
+	dev_dbg(tty->dev, "%s\n", __func__);
 
-	dev_dbg(&acm->control->dev, "%s\n", __func__);
+	acm = acm_get_by_index(tty->index);
+	if (!acm)
+		return -ENODEV;
 
-	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+	retval = tty_init_termios(tty);
+	if (retval)
+		goto error_init_termios;
 
 	tty->driver_data = acm;
-	tty_port_tty_set(&acm->port, tty);
 
-	if (usb_autopm_get_interface(acm->control) < 0)
-		goto early_bail;
-	else
-		acm->control->needs_remote_wakeup = 1;
+	/* Final install (we use the default method) */
+	tty_driver_kref_get(driver);
+	tty->count++;
+	driver->ttys[tty->index] = tty;
+
+	return 0;
+
+error_init_termios:
+	tty_port_put(&acm->port);
+	return retval;
+}
+
+static int acm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct acm *acm = tty->driver_data;
+
+	dev_dbg(tty->dev, "%s\n", __func__);
+
+	return tty_port_open(&acm->port, tty, filp);
+}
+
+static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	struct acm *acm = container_of(port, struct acm, port);
+	int retval = -ENODEV;
+
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
 
 	mutex_lock(&acm->mutex);
-	if (acm->port.count++) {
-		mutex_unlock(&acm->mutex);
-		usb_autopm_put_interface(acm->control);
-		goto out;
-	}
+	if (acm->disconnected)
+		goto disconnected;
+
+	retval = usb_autopm_get_interface(acm->control);
+	if (retval)
+		goto error_get_interface;
+
+	/*
+	 * FIXME: Why do we need this? Allocating 64K of physically contiguous
+	 * memory is really nasty...
+	 */
+	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+	acm->control->needs_remote_wakeup = 1;
 
 	acm->ctrlurb->dev = acm->dev;
 	if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
 		dev_err(&acm->control->dev,
 			"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
-		goto bail_out;
+		goto error_submit_urb;
 	}
 
-	if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
+	acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
+	if (acm_set_control(acm, acm->ctrlout) < 0 &&
 	    (acm->ctrl_caps & USB_CDC_CAP_LINE))
-		goto bail_out;
+		goto error_set_control;
 
 	usb_autopm_put_interface(acm->control);
 
 	if (acm_submit_read_urbs(acm, GFP_KERNEL))
-		goto bail_out;
-
-	set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
-	rv = tty_port_block_til_ready(&acm->port, tty, filp);
+		goto error_submit_read_urbs;
 
 	mutex_unlock(&acm->mutex);
-out:
-	mutex_unlock(&open_mutex);
-	return rv;
 
-bail_out:
-	acm->port.count--;
-	mutex_unlock(&acm->mutex);
+	return 0;
+
+error_submit_read_urbs:
+	acm->ctrlout = 0;
+	acm_set_control(acm, acm->ctrlout);
+error_set_control:
+	usb_kill_urb(acm->ctrlurb);
+error_submit_urb:
 	usb_autopm_put_interface(acm->control);
-early_bail:
-	mutex_unlock(&open_mutex);
-	tty_port_tty_set(&acm->port, NULL);
-	return -EIO;
+error_get_interface:
+disconnected:
+	mutex_unlock(&acm->mutex);
+	return retval;
 }
 
-static void acm_tty_unregister(struct acm *acm)
+static void acm_port_destruct(struct tty_port *port)
 {
-	int i;
+	struct acm *acm = container_of(port, struct acm, port);
+
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
 
 	tty_unregister_device(acm_tty_driver, acm->minor);
+	acm_release_minor(acm);
 	usb_put_intf(acm->control);
-	acm_table[acm->minor] = NULL;
-	usb_free_urb(acm->ctrlurb);
-	for (i = 0; i < ACM_NW; i++)
-		usb_free_urb(acm->wb[i].urb);
-	for (i = 0; i < acm->rx_buflimit; i++)
-		usb_free_urb(acm->read_urbs[i]);
 	kfree(acm->country_codes);
 	kfree(acm);
 }
 
-static void acm_port_down(struct acm *acm)
+static void acm_port_shutdown(struct tty_port *port)
 {
+	struct acm *acm = container_of(port, struct acm, port);
 	int i;
 
-	if (acm->dev) {
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
+
+	mutex_lock(&acm->mutex);
+	if (!acm->disconnected) {
 		usb_autopm_get_interface(acm->control);
 		acm_set_control(acm, acm->ctrlout = 0);
 		usb_kill_urb(acm->ctrlurb);
@@ -550,40 +631,28 @@ static void acm_port_down(struct acm *acm)
 		acm->control->needs_remote_wakeup = 0;
 		usb_autopm_put_interface(acm->control);
 	}
+	mutex_unlock(&acm->mutex);
+}
+
+static void acm_tty_cleanup(struct tty_struct *tty)
+{
+	struct acm *acm = tty->driver_data;
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
+	tty_port_put(&acm->port);
 }
 
 static void acm_tty_hangup(struct tty_struct *tty)
 {
 	struct acm *acm = tty->driver_data;
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
 	tty_port_hangup(&acm->port);
-	mutex_lock(&open_mutex);
-	acm_port_down(acm);
-	mutex_unlock(&open_mutex);
 }
 
 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 {
 	struct acm *acm = tty->driver_data;
-
-	/* Perform the closing process and see if we need to do the hardware
-	   shutdown */
-	if (!acm)
-		return;
-
-	mutex_lock(&open_mutex);
-	if (tty_port_close_start(&acm->port, tty, filp) == 0) {
-		if (!acm->dev) {
-			tty_port_tty_set(&acm->port, NULL);
-			acm_tty_unregister(acm);
-			tty->driver_data = NULL;
-		}
-		mutex_unlock(&open_mutex);
-		return;
-	}
-	acm_port_down(acm);
-	tty_port_close_end(&acm->port, tty);
-	tty_port_tty_set(&acm->port, NULL);
-	mutex_unlock(&open_mutex);
+	dev_dbg(&acm->control->dev, "%s\n", __func__);
+	tty_port_close(&acm->port, tty, filp);
 }
 
 static int acm_tty_write(struct tty_struct *tty,
@@ -595,8 +664,6 @@ static int acm_tty_write(struct tty_struct *tty,
 	int wbn;
 	struct acm_wb *wb;
 
-	if (!ACM_READY(acm))
-		return -EINVAL;
 	if (!count)
 		return 0;
 
@@ -625,8 +692,6 @@ static int acm_tty_write(struct tty_struct *tty,
 static int acm_tty_write_room(struct tty_struct *tty)
 {
 	struct acm *acm = tty->driver_data;
-	if (!ACM_READY(acm))
-		return -EINVAL;
 	/*
 	 * Do not let the line discipline to know that we have a reserve,
 	 * or it might get too enthusiastic.
@@ -637,7 +702,11 @@ static int acm_tty_write_room(struct tty_struct *tty)
 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
 {
 	struct acm *acm = tty->driver_data;
-	if (!ACM_READY(acm))
+	/*
+	 * if the device was unplugged then any remaining characters fell out
+	 * of the connector ;)
+	 */
+	if (acm->disconnected)
 		return 0;
 	/*
 	 * This is inaccurate (overcounts), but it works.
@@ -649,9 +718,6 @@ static void acm_tty_throttle(struct tty_struct *tty)
 {
 	struct acm *acm = tty->driver_data;
 
-	if (!ACM_READY(acm))
-		return;
-
 	spin_lock_irq(&acm->read_lock);
 	acm->throttle_req = 1;
 	spin_unlock_irq(&acm->read_lock);
@@ -662,9 +728,6 @@ static void acm_tty_unthrottle(struct tty_struct *tty)
 	struct acm *acm = tty->driver_data;
 	unsigned int was_throttled;
 
-	if (!ACM_READY(acm))
-		return;
-
 	spin_lock_irq(&acm->read_lock);
 	was_throttled = acm->throttled;
 	acm->throttled = 0;
@@ -679,8 +742,7 @@ static int acm_tty_break_ctl(struct tty_struct *tty, int state)
 {
 	struct acm *acm = tty->driver_data;
 	int retval;
-	if (!ACM_READY(acm))
-		return -EINVAL;
+
 	retval = acm_send_break(acm, state ? 0xffff : 0);
 	if (retval < 0)
 		dev_dbg(&acm->control->dev, "%s - send break failed\n",
@@ -692,9 +754,6 @@ static int acm_tty_tiocmget(struct tty_struct *tty)
 {
 	struct acm *acm = tty->driver_data;
 
-	if (!ACM_READY(acm))
-		return -EINVAL;
-
 	return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
 	       (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
 	       (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
@@ -709,9 +768,6 @@ static int acm_tty_tiocmset(struct tty_struct *tty,
 	struct acm *acm = tty->driver_data;
 	unsigned int newctrl;
 
-	if (!ACM_READY(acm))
-		return -EINVAL;
-
 	newctrl = acm->ctrlout;
 	set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
 					(set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
@@ -728,11 +784,6 @@ static int acm_tty_tiocmset(struct tty_struct *tty,
 static int acm_tty_ioctl(struct tty_struct *tty,
 					unsigned int cmd, unsigned long arg)
 {
-	struct acm *acm = tty->driver_data;
-
-	if (!ACM_READY(acm))
-		return -EINVAL;
-
 	return -ENOIOCTLCMD;
 }
 
@@ -756,9 +807,6 @@ static void acm_tty_set_termios(struct tty_struct *tty,
 	struct usb_cdc_line_coding newline;
 	int newctrl = acm->ctrlout;
 
-	if (!ACM_READY(acm))
-		return;
-
 	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
 	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
 	newline.bParityType = termios->c_cflag & PARENB ?
@@ -788,6 +836,12 @@ static void acm_tty_set_termios(struct tty_struct *tty,
 	}
 }
 
+static const struct tty_port_operations acm_port_ops = {
+	.shutdown = acm_port_shutdown,
+	.activate = acm_port_activate,
+	.destruct = acm_port_destruct,
+};
+
 /*
  * USB probe and disconnect routines.
  */
@@ -1047,12 +1101,6 @@ skip_normal_probe:
 	}
 made_compressed_probe:
 	dev_dbg(&intf->dev, "interfaces are valid\n");
-	for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
-
-	if (minor == ACM_TTY_MINORS) {
-		dev_err(&intf->dev, "no more free acm devices\n");
-		return -ENODEV;
-	}
 
 	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
 	if (acm == NULL) {
@@ -1060,6 +1108,13 @@ made_compressed_probe:
 		goto alloc_fail;
 	}
 
+	minor = acm_alloc_minor(acm);
+	if (minor == ACM_TTY_MINORS) {
+		dev_err(&intf->dev, "no more free acm devices\n");
+		kfree(acm);
+		return -ENODEV;
+	}
+
 	ctrlsize = usb_endpoint_maxp(epctrl);
 	readsize = usb_endpoint_maxp(epread) *
 				(quirks == SINGLE_RX_URB ? 1 : 2);
@@ -1218,8 +1273,6 @@ skip_countries:
 	usb_get_intf(control_interface);
 	tty_register_device(acm_tty_driver, minor, &control_interface->dev);
 
-	acm_table[minor] = acm;
-
 	return 0;
 alloc_fail7:
 	for (i = 0; i < ACM_NW; i++)
@@ -1234,6 +1287,7 @@ alloc_fail5:
 alloc_fail4:
 	usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 alloc_fail2:
+	acm_release_minor(acm);
 	kfree(acm);
 alloc_fail:
 	return -ENOMEM;
@@ -1259,12 +1313,16 @@ static void acm_disconnect(struct usb_interface *intf)
 	struct acm *acm = usb_get_intfdata(intf);
 	struct usb_device *usb_dev = interface_to_usbdev(intf);
 	struct tty_struct *tty;
+	int i;
+
+	dev_dbg(&intf->dev, "%s\n", __func__);
 
 	/* sibling interface is already cleaning up */
 	if (!acm)
 		return;
 
-	mutex_lock(&open_mutex);
+	mutex_lock(&acm->mutex);
+	acm->disconnected = true;
 	if (acm->country_codes) {
 		device_remove_file(&acm->control->dev,
 				&dev_attr_wCountryCodes);
@@ -1272,33 +1330,32 @@ static void acm_disconnect(struct usb_interface *intf)
 				&dev_attr_iCountryCodeRelDate);
 	}
 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
-	acm->dev = NULL;
 	usb_set_intfdata(acm->control, NULL);
 	usb_set_intfdata(acm->data, NULL);
+	mutex_unlock(&acm->mutex);
+
+	tty = tty_port_tty_get(&acm->port);
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
 
 	stop_data_traffic(acm);
 
+	usb_free_urb(acm->ctrlurb);
+	for (i = 0; i < ACM_NW; i++)
+		usb_free_urb(acm->wb[i].urb);
+	for (i = 0; i < acm->rx_buflimit; i++)
+		usb_free_urb(acm->read_urbs[i]);
 	acm_write_buffers_free(acm);
-	usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer,
-			  acm->ctrl_dma);
+	usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 	acm_read_buffers_free(acm);
 
 	if (!acm->combined_interfaces)
 		usb_driver_release_interface(&acm_driver, intf == acm->control ?
 					acm->data : acm->control);
 
-	if (acm->port.count == 0) {
-		acm_tty_unregister(acm);
-		mutex_unlock(&open_mutex);
-		return;
-	}
-
-	mutex_unlock(&open_mutex);
-	tty = tty_port_tty_get(&acm->port);
-	if (tty) {
-		tty_hangup(tty);
-		tty_kref_put(tty);
-	}
+	tty_port_put(&acm->port);
 }
 
 #ifdef CONFIG_PM
@@ -1325,16 +1382,10 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message)
 
 	if (cnt)
 		return 0;
-	/*
-	we treat opened interfaces differently,
-	we must guard against open
-	*/
-	mutex_lock(&acm->mutex);
 
-	if (acm->port.count)
+	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
 		stop_data_traffic(acm);
 
-	mutex_unlock(&acm->mutex);
 	return 0;
 }
 
@@ -1353,8 +1404,7 @@ static int acm_resume(struct usb_interface *intf)
 	if (cnt)
 		return 0;
 
-	mutex_lock(&acm->mutex);
-	if (acm->port.count) {
+	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
 		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
 
 		spin_lock_irq(&acm->write_lock);
@@ -1378,7 +1428,6 @@ static int acm_resume(struct usb_interface *intf)
 	}
 
 err_out:
-	mutex_unlock(&acm->mutex);
 	return rv;
 }
 
@@ -1387,15 +1436,14 @@ static int acm_reset_resume(struct usb_interface *intf)
 	struct acm *acm = usb_get_intfdata(intf);
 	struct tty_struct *tty;
 
-	mutex_lock(&acm->mutex);
-	if (acm->port.count) {
+	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
 		tty = tty_port_tty_get(&acm->port);
 		if (tty) {
 			tty_hangup(tty);
 			tty_kref_put(tty);
 		}
 	}
-	mutex_unlock(&acm->mutex);
+
 	return acm_resume(intf);
 }
 
@@ -1594,8 +1642,10 @@ static struct usb_driver acm_driver = {
  */
 
 static const struct tty_operations acm_ops = {
+	.install =		acm_tty_install,
 	.open =			acm_tty_open,
 	.close =		acm_tty_close,
+	.cleanup =		acm_tty_cleanup,
 	.hangup =		acm_tty_hangup,
 	.write =		acm_tty_write,
 	.write_room =		acm_tty_write_room,
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index ca7937f26e27..35ef887b7417 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -101,6 +101,7 @@ struct acm {
 	int transmitting;
 	spinlock_t write_lock;
 	struct mutex mutex;
+	bool disconnected;
 	struct usb_cdc_line_coding line;		/* bits, stop, parity */
 	struct work_struct work;			/* work queue entry for line discipline waking up */
 	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */