usb: gadgetfs: Convert semaphore to mutex

The semaphore data->lock is semantically a mutex. Convert it to a real
mutex.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/inode.c

@@ -194,7 +194,7 @@ enum ep_state {
 };
 
 struct ep_data {
-	struct semaphore		lock;
+	struct mutex			lock;
 	enum ep_state			state;
 	atomic_t			count;
 	struct dev_data			*dev;
@@ -298,10 +298,10 @@ get_ready_ep (unsigned f_flags, struct ep_data *epdata)
 	int	val;
 
 	if (f_flags & O_NONBLOCK) {
-		if (down_trylock (&epdata->lock) != 0)
+		if (!mutex_trylock(&epdata->lock))
 			goto nonblock;
 		if (epdata->state != STATE_EP_ENABLED) {
-			up (&epdata->lock);
+			mutex_unlock(&epdata->lock);
 nonblock:
 			val = -EAGAIN;
 		} else
@@ -309,7 +309,8 @@ nonblock:
 		return val;
 	}
 
-	if ((val = down_interruptible (&epdata->lock)) < 0)
+	val = mutex_lock_interruptible(&epdata->lock);
+	if (val < 0)
 		return val;
 
 	switch (epdata->state) {
@@ -323,7 +324,7 @@ nonblock:
 		// FALLTHROUGH
 	case STATE_EP_UNBOUND:			/* clean disconnect */
 		val = -ENODEV;
-		up (&epdata->lock);
+		mutex_unlock(&epdata->lock);
 	}
 	return val;
 }
@@ -393,7 +394,7 @@ ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		if (likely (data->ep != NULL))
 			usb_ep_set_halt (data->ep);
 		spin_unlock_irq (&data->dev->lock);
-		up (&data->lock);
+		mutex_unlock(&data->lock);
 		return -EBADMSG;
 	}
 
@@ -411,7 +412,7 @@ ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		value = -EFAULT;
 
 free1:
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	kfree (kbuf);
 	return value;
 }
@@ -436,7 +437,7 @@ ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 		if (likely (data->ep != NULL))
 			usb_ep_set_halt (data->ep);
 		spin_unlock_irq (&data->dev->lock);
-		up (&data->lock);
+		mutex_unlock(&data->lock);
 		return -EBADMSG;
 	}
 
@@ -455,7 +456,7 @@ ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	VDEBUG (data->dev, "%s write %zu IN, status %d\n",
 		data->name, len, (int) value);
 free1:
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	kfree (kbuf);
 	return value;
 }
@@ -466,7 +467,8 @@ ep_release (struct inode *inode, struct file *fd)
 	struct ep_data		*data = fd->private_data;
 	int value;
 
-	if ((value = down_interruptible(&data->lock)) < 0)
+	value = mutex_lock_interruptible(&data->lock);
+	if (value < 0)
 		return value;
 
 	/* clean up if this can be reopened */
@@ -476,7 +478,7 @@ ep_release (struct inode *inode, struct file *fd)
 		data->hs_desc.bDescriptorType = 0;
 		usb_ep_disable(data->ep);
 	}
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	put_ep (data);
 	return 0;
 }
@@ -507,7 +509,7 @@ static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
 	} else
 		status = -ENODEV;
 	spin_unlock_irq (&data->dev->lock);
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	return status;
 }
 
@@ -673,7 +675,7 @@ fail:
 		value = -ENODEV;
 	spin_unlock_irq(&epdata->dev->lock);
 
-	up(&epdata->lock);
+	mutex_unlock(&epdata->lock);
 
 	if (unlikely(value)) {
 		kfree(priv);
@@ -765,7 +767,8 @@ ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	u32			tag;
 	int			value, length = len;
 
-	if ((value = down_interruptible (&data->lock)) < 0)
+	value = mutex_lock_interruptible(&data->lock);
+	if (value < 0)
 		return value;
 
 	if (data->state != STATE_EP_READY) {
@@ -854,7 +857,7 @@ fail:
 		data->desc.bDescriptorType = 0;
 		data->hs_desc.bDescriptorType = 0;
 	}
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	return value;
 fail0:
 	value = -EINVAL;
@@ -870,7 +873,7 @@ ep_open (struct inode *inode, struct file *fd)
 	struct ep_data		*data = inode->i_private;
 	int			value = -EBUSY;
 
-	if (down_interruptible (&data->lock) != 0)
+	if (mutex_lock_interruptible(&data->lock) != 0)
 		return -EINTR;
 	spin_lock_irq (&data->dev->lock);
 	if (data->dev->state == STATE_DEV_UNBOUND)
@@ -885,7 +888,7 @@ ep_open (struct inode *inode, struct file *fd)
 		DBG (data->dev, "%s state %d\n",
 			data->name, data->state);
 	spin_unlock_irq (&data->dev->lock);
-	up (&data->lock);
+	mutex_unlock(&data->lock);
 	return value;
 }
 
@@ -1631,7 +1634,7 @@ static int activate_ep_files (struct dev_data *dev)
 		if (!data)
 			goto enomem0;
 		data->state = STATE_EP_DISABLED;
-		init_MUTEX (&data->lock);
+		mutex_init(&data->lock);
 		init_waitqueue_head (&data->wait);
 
 		strncpy (data->name, ep->name, sizeof (data->name) - 1);