From 1bac6d670bf3b07110b690b8afb094f54fd9b520 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oliver@neukum.org>
Date: Thu, 25 Oct 2007 15:48:39 +0200
Subject: [PATCH] --- yaml --- r: 72587 b: refs/heads/master c:
 78663ecc344b4694dd737deb682e81312a0684b6 h: refs/heads/master i:   72585:
 66af5d6f2c4bc8e83497c2b5c464725c44b3aa47   72583:
 d9bfe7fafe5681a3a7dd59494118c50b3bf6ecf4 v: v3

---
 [refs]                                |  2 +-
 trunk/drivers/usb/misc/legousbtower.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index b4bf0f043878..206ef426cb07 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 03f36e885fc26cb0ea299fb6df5171a51e814548
+refs/heads/master: 78663ecc344b4694dd737deb682e81312a0684b6
diff --git a/trunk/drivers/usb/misc/legousbtower.c b/trunk/drivers/usb/misc/legousbtower.c
index 561970b889a5..aab320085ebf 100644
--- a/trunk/drivers/usb/misc/legousbtower.c
+++ b/trunk/drivers/usb/misc/legousbtower.c
@@ -198,6 +198,7 @@ static struct usb_device_id tower_table [] = {
 };
 
 MODULE_DEVICE_TABLE (usb, tower_table);
+static DEFINE_MUTEX(open_disc_mutex);
 
 #define LEGO_USB_TOWER_MINOR_BASE	160
 
@@ -350,25 +351,31 @@ static int tower_open (struct inode *inode, struct file *file)
 		goto exit;
 	}
 
+	mutex_lock(&open_disc_mutex);
 	dev = usb_get_intfdata(interface);
 
 	if (!dev) {
+		mutex_unlock(&open_disc_mutex);
 		retval = -ENODEV;
 		goto exit;
 	}
 
 	/* lock this device */
 	if (down_interruptible (&dev->sem)) {
+		mutex_unlock(&open_disc_mutex);
 	        retval = -ERESTARTSYS;
 		goto exit;
 	}
 
+
 	/* allow opening only once */
 	if (dev->open_count) {
+		mutex_unlock(&open_disc_mutex);
 		retval = -EBUSY;
 		goto unlock_exit;
 	}
 	dev->open_count = 1;
+	mutex_unlock(&open_disc_mutex);
 
 	/* reset the tower */
 	result = usb_control_msg (dev->udev,
@@ -437,9 +444,10 @@ static int tower_release (struct inode *inode, struct file *file)
 	if (dev == NULL) {
 		dbg(1, "%s: object is NULL", __FUNCTION__);
 		retval = -ENODEV;
-		goto exit;
+		goto exit_nolock;
 	}
 
+	mutex_lock(&open_disc_mutex);
 	if (down_interruptible (&dev->sem)) {
 	        retval = -ERESTARTSYS;
 		goto exit;
@@ -468,6 +476,8 @@ static int tower_release (struct inode *inode, struct file *file)
 	up (&dev->sem);
 
 exit:
+	mutex_unlock(&open_disc_mutex);
+exit_nolock:
 	dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
 	return retval;
 }
@@ -989,6 +999,7 @@ static void tower_disconnect (struct usb_interface *interface)
 	dbg(2, "%s: enter", __FUNCTION__);
 
 	dev = usb_get_intfdata (interface);
+	mutex_lock(&open_disc_mutex);
 	usb_set_intfdata (interface, NULL);
 
 	minor = dev->minor;
@@ -997,6 +1008,7 @@ static void tower_disconnect (struct usb_interface *interface)
 	usb_deregister_dev (interface, &tower_class);
 
 	down (&dev->sem);
+	mutex_unlock(&open_disc_mutex);
 
 	/* if the device is not opened, then we clean up right now */
 	if (!dev->open_count) {