diff --git a/[refs] b/[refs]
index 7ca2c43f094f..4862a143b7ac 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 70ffa16e604bab22b12bf72cb7796f1dd01ec335
+refs/heads/master: 16750c2f32e3fd879fce787a13900f11633ef9af
diff --git a/trunk/drivers/telephony/phonedev.c b/trunk/drivers/telephony/phonedev.c
index bcea8d9b718c..4d74ba36c3a1 100644
--- a/trunk/drivers/telephony/phonedev.c
+++ b/trunk/drivers/telephony/phonedev.c
@@ -23,6 +23,7 @@
 #include <linux/errno.h>
 #include <linux/phonedev.h>
 #include <linux/init.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
@@ -53,6 +54,7 @@ static int phone_open(struct inode *inode, struct file *file)
 	if (minor >= PHONE_NUM_DEVICES)
 		return -ENODEV;
 
+	lock_kernel();
 	mutex_lock(&phone_lock);
 	p = phone_device[minor];
 	if (p)
@@ -79,6 +81,7 @@ static int phone_open(struct inode *inode, struct file *file)
 	fops_put(old_fops);
 end:
 	mutex_unlock(&phone_lock);
+	unlock_kernel();
 	return err;
 }