diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 558890ada0e5..c766b4a2630b 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -33,21 +33,20 @@ static DEFINE_MUTEX(init_usb_class_mutex);
 
 static int usb_open(struct inode *inode, struct file *file)
 {
-	int err = -ENODEV;
+	int err;
 	const struct file_operations *new_fops;
 
 	down_read(&minor_rwsem);
 	new_fops = fops_get(usb_minors[iminor(inode)]);
+	up_read(&minor_rwsem);
 
 	if (!new_fops)
-		goto done;
+		return -ENODEV;
 
 	replace_fops(file, new_fops);
 	/* Curiouser and curiouser... NULL ->open() as "no device" ? */
 	if (file->f_op->open)
 		err = file->f_op->open(inode, file);
- done:
-	up_read(&minor_rwsem);
 	return err;
 }
 
diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index 2ca4e86c7b9f..3421fbc7c61d 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -488,31 +488,40 @@ static void free_imon_context(struct imon_context *ictx)
 	dev_dbg(dev, "%s: iMON context freed\n", __func__);
 }
 
+static struct imon_context *get_ictx_from_inode(struct inode *inode)
+{
+	struct usb_interface *interface;
+	struct imon_context *ictx = NULL;
+	int subminor;
+
+	subminor = iminor(inode);
+	interface = usb_find_interface(&imon_driver, subminor);
+	if (!interface) {
+		pr_err("could not find interface for minor %d\n", subminor);
+		return NULL;
+	}
+	ictx = usb_get_intfdata(interface);
+
+	if (!ictx)
+		pr_err("no context found for minor %d\n", subminor);
+	return ictx;
+}
+
 /*
  * Called when the Display device (e.g. /dev/lcd0)
  * is opened by the application.
  */
 static int display_open(struct inode *inode, struct file *file)
 {
-	struct usb_interface *interface;
 	struct imon_context *ictx = NULL;
-	int subminor;
 	int retval = 0;
 
 	/* prevent races with disconnect */
 	mutex_lock(&driver_lock);
 
-	subminor = iminor(inode);
-	interface = usb_find_interface(&imon_driver, subminor);
-	if (!interface) {
-		pr_err("could not find interface for minor %d\n", subminor);
-		retval = -ENODEV;
-		goto exit;
-	}
-	ictx = usb_get_intfdata(interface);
+	ictx = get_ictx_from_inode(inode);
 
 	if (!ictx) {
-		pr_err("no context found for minor %d\n", subminor);
 		retval = -ENODEV;
 		goto exit;
 	}
@@ -547,11 +556,14 @@ static int display_close(struct inode *inode, struct file *file)
 	struct imon_context *ictx = NULL;
 	int retval = 0;
 
-	ictx = file->private_data;
+	/* prevent races with disconnect */
+	mutex_lock(&driver_lock);
+
+	ictx = get_ictx_from_inode(inode);
 
 	if (!ictx) {
-		pr_err("no context for device\n");
-		return -ENODEV;
+		retval = -ENODEV;
+		goto exit;
 	}
 
 	mutex_lock(&ictx->lock);
@@ -568,6 +580,9 @@ static int display_close(struct inode *inode, struct file *file)
 	}
 
 	mutex_unlock(&ictx->lock);
+
+exit:
+	mutex_unlock(&driver_lock);
 	return retval;
 }
 
@@ -584,6 +599,7 @@ static int send_packet(struct imon_context *ictx)
 	int retval = 0;
 	struct usb_ctrlrequest *control_req = NULL;
 
+	lockdep_assert_held_once(&ictx->lock);
 	/* Check if we need to use control or interrupt urb */
 	if (!ictx->tx_control) {
 		pipe = usb_sndintpipe(ictx->usbdev_intf0,