From 7495f693770cde0618962ea2e5d85e8db3d2282f Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Fri, 16 May 2008 14:03:05 -0600
Subject: [PATCH] --- yaml --- r: 100309 b: refs/heads/master c:
 4541b5ec9f631a143cdea862d07ddfc3cdac36f2 h: refs/heads/master i:   100307:
 c815a4aa30d215e86a0bc13ecc78f4f9612d4dc2 v: v3

---
 [refs]                       | 2 +-
 trunk/drivers/misc/phantom.c | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 9870ead23baf..274cd2b93241 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 057e7c7ff9f91a36a761588c53826bd6a710aeba
+refs/heads/master: 4541b5ec9f631a143cdea862d07ddfc3cdac36f2
diff --git a/trunk/drivers/misc/phantom.c b/trunk/drivers/misc/phantom.c
index 71d1c84e2fa8..186162470090 100644
--- a/trunk/drivers/misc/phantom.c
+++ b/trunk/drivers/misc/phantom.c
@@ -22,6 +22,7 @@
 #include <linux/interrupt.h>
 #include <linux/cdev.h>
 #include <linux/phantom.h>
+#include <linux/smp_lock.h>
 
 #include <asm/atomic.h>
 #include <asm/io.h>
@@ -212,13 +213,17 @@ static int phantom_open(struct inode *inode, struct file *file)
 	struct phantom_device *dev = container_of(inode->i_cdev,
 			struct phantom_device, cdev);
 
+	lock_kernel();
 	nonseekable_open(inode, file);
 
-	if (mutex_lock_interruptible(&dev->open_lock))
+	if (mutex_lock_interruptible(&dev->open_lock)) {
+		unlock_kernel();
 		return -ERESTARTSYS;
+	}
 
 	if (dev->opened) {
 		mutex_unlock(&dev->open_lock);
+		unlock_kernel();
 		return -EINVAL;
 	}
 
@@ -229,7 +234,7 @@ static int phantom_open(struct inode *inode, struct file *file)
 	atomic_set(&dev->counter, 0);
 	dev->opened++;
 	mutex_unlock(&dev->open_lock);
-
+	unlock_kernel();
 	return 0;
 }