diff --git a/[refs] b/[refs]
index d946f764793f..e29800848b64 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0410e689b19b6ca010a6a44abfa820968ae15733
+refs/heads/master: f8f2c79d594463427f7114cedb1555110d547d89
diff --git a/trunk/drivers/char/sonypi.c b/trunk/drivers/char/sonypi.c
index 58533de59027..85e0eb76eeab 100644
--- a/trunk/drivers/char/sonypi.c
+++ b/trunk/drivers/char/sonypi.c
@@ -49,6 +49,7 @@
 #include <linux/err.h>
 #include <linux/kfifo.h>
 #include <linux/platform_device.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -906,12 +907,14 @@ static int sonypi_misc_release(struct inode *inode, struct file *file)
 
 static int sonypi_misc_open(struct inode *inode, struct file *file)
 {
+	lock_kernel();
 	mutex_lock(&sonypi_device.lock);
 	/* Flush input queue on first open */
 	if (!sonypi_device.open_count)
 		kfifo_reset(sonypi_device.fifo);
 	sonypi_device.open_count++;
 	mutex_unlock(&sonypi_device.lock);
+	unlock_kernel();
 	return 0;
 }