1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index a54c3cb804ce..68df9ac76699 100644
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/completion.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <linux/usb.h>
 
@@ -226,16 +227,20 @@ static int idmouse_open(struct inode *inode, struct file *file)
         struct usb_interface *interface;
         int result;
 
+        lock_kernel();
         /* get the interface from minor number and driver information */
         interface = usb_find_interface (&idmouse_driver, iminor (inode));
-        if (!interface)
+        if (!interface) {
+                unlock_kernel();
                 return -ENODEV;
+        }
 
         mutex_lock(&open_disc_mutex);
         /* get the device information block from the interface */
         dev = usb_get_intfdata(interface);
         if (!dev) {
                 mutex_unlock(&open_disc_mutex);
+                unlock_kernel();
                 return -ENODEV;
         }
 
@@ -272,6 +277,7 @@ error:
 
         /* unlock this device */
         mutex_unlock(&dev->lock);
+        unlock_kernel();
         return result;
 }