1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 93b5f85d7ceb..d53f9499f936 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -56,6 +56,7 @@
 #include <linux/slab.h>
 #include <linux/lp.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #undef DEBUG
 #include <linux/usb.h>
 
@@ -395,6 +396,7 @@ static int usblp_open(struct inode *inode, struct file *file)
         if (minor < 0)
                 return -ENODEV;
 
+        lock_kernel();
         mutex_lock (&usblp_mutex);
 
         retval = -ENODEV;
@@ -434,6 +436,7 @@ static int usblp_open(struct inode *inode, struct file *file)
         }
 out:
         mutex_unlock (&usblp_mutex);
+        unlock_kernel();
         return retval;
 }