1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c
index 7c0bd13eccb2..8de32df5978a 100644
--- a/drivers/usb/misc/ldusb.c
+++ b/drivers/usb/misc/ldusb.c
@@ -33,6 +33,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <linux/input.h>
@@ -296,12 +297,14 @@ static int ld_usb_open(struct inode *inode, struct file *file)
         int retval;
         struct usb_interface *interface;
 
+        lock_kernel();
         nonseekable_open(inode, file);
         subminor = iminor(inode);
 
         interface = usb_find_interface(&ld_usb_driver, subminor);
 
         if (!interface) {
+                unlock_kernel();
                 err("%s - error, can't find device for minor %d\n",
                      __func__, subminor);
                 return -ENODEV;
@@ -309,12 +312,16 @@ static int ld_usb_open(struct inode *inode, struct file *file)
 
         dev = usb_get_intfdata(interface);
 
-        if (!dev)
+        if (!dev) {
+                unlock_kernel();
                 return -ENODEV;
+        }
 
         /* lock this device */
-        if (mutex_lock_interruptible(&dev->mutex))
+        if (mutex_lock_interruptible(&dev->mutex)) {
+                unlock_kernel();
                 return -ERESTARTSYS;
+        }
 
         /* allow opening only once */
         if (dev->open_count) {
@@ -353,6 +360,7 @@ static int ld_usb_open(struct inode *inode, struct file *file)
 
 unlock_exit:
         mutex_unlock(&dev->mutex);
+        unlock_kernel();
 
         return retval;
 }