USB: misc: legousbtower: semaphore to mutex (18bcbcfe) · Commits · 戴 / test

drivers/usb/misc/legousbtower.c

+16 −14

Original line number	Diff line number	Diff line
		@@ -205,7 +205,7 @@ static DEFINE_MUTEX(open_disc_mutex);

		/* Structure to hold all of our device specific stuff */
		struct lego_usb_tower {
		struct semaphore sem; /* locks this structure */
		struct mutex lock; /* locks this structure */
		struct usb_device* udev; /* save off the usb device pointer */
		unsigned char minor; /* the starting minor number for this device */

		@@ -361,7 +361,7 @@ static int tower_open (struct inode inode, struct file file)
		}

		/* lock this device */
		if (down_interruptible (&dev->sem)) {
		if (mutex_lock_interruptible(&dev->lock)) {
		mutex_unlock(&open_disc_mutex);
		retval = -ERESTARTSYS;
		goto exit;
		@@ -421,7 +421,7 @@ static int tower_open (struct inode inode, struct file file)
		file->private_data = dev;

		unlock_exit:
		up (&dev->sem);
		mutex_unlock(&dev->lock);

		exit:
		dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval);
		@@ -448,7 +448,7 @@ static int tower_release (struct inode inode, struct file file)
		}

		mutex_lock(&open_disc_mutex);
		if (down_interruptible (&dev->sem)) {
		if (mutex_lock_interruptible(&dev->lock)) {
		retval = -ERESTARTSYS;
		goto exit;
		}
		@@ -460,7 +460,9 @@ static int tower_release (struct inode inode, struct file file)
		}
		if (dev->udev == NULL) {
		/* the device was unplugged before the file was released */
		up (&dev->sem); /* unlock here as tower_delete frees dev */

		/* unlock here as tower_delete frees dev */
		mutex_unlock(&dev->lock);
		tower_delete (dev);
		goto exit;
		}
		@@ -473,7 +475,7 @@ static int tower_release (struct inode inode, struct file file)
		dev->open_count = 0;

		unlock_exit:
		up (&dev->sem);
		mutex_unlock(&dev->lock);

		exit:
		mutex_unlock(&open_disc_mutex);
		@@ -586,7 +588,7 @@ static ssize_t tower_read (struct file file, char __user buffer, size_t count,
		dev = (struct lego_usb_tower *)file->private_data;

		/* lock this object */
		if (down_interruptible (&dev->sem)) {
		if (mutex_lock_interruptible(&dev->lock)) {
		retval = -ERESTARTSYS;
		goto exit;
		}
		@@ -653,7 +655,7 @@ static ssize_t tower_read (struct file file, char __user buffer, size_t count,

		unlock_exit:
		/* unlock the device */
		up (&dev->sem);
		mutex_unlock(&dev->lock);

		exit:
		dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
		@@ -675,7 +677,7 @@ static ssize_t tower_write (struct file file, const char __user buffer, size_t
		dev = (struct lego_usb_tower *)file->private_data;

		/* lock this object */
		if (down_interruptible (&dev->sem)) {
		if (mutex_lock_interruptible(&dev->lock)) {
		retval = -ERESTARTSYS;
		goto exit;
		}
		@@ -737,7 +739,7 @@ static ssize_t tower_write (struct file file, const char __user buffer, size_t

		unlock_exit:
		/* unlock the device */
		up (&dev->sem);
		mutex_unlock(&dev->lock);

		exit:
		dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
		@@ -862,7 +864,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
		goto exit;
		}

		init_MUTEX (&dev->sem);
		mutex_init(&dev->lock);

		dev->udev = udev;
		dev->open_count = 0;
		@@ -1007,16 +1009,16 @@ static void tower_disconnect (struct usb_interface *interface)
		/* give back our minor */
		usb_deregister_dev (interface, &tower_class);

		down (&dev->sem);
		mutex_lock(&dev->lock);
		mutex_unlock(&open_disc_mutex);

		/* if the device is not opened, then we clean up right now */
		if (!dev->open_count) {
		up (&dev->sem);
		mutex_unlock(&dev->lock);
		tower_delete (dev);
		} else {
		dev->udev = NULL;
		up (&dev->sem);
		mutex_unlock(&dev->lock);
		}

		info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE));

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