1 files changed, 7 insertions, 2 deletions

diff --git a/sound/oss/sh_dac_audio.c b/sound/oss/sh_dac_audio.c
index 4153752507e3..8f0be4053a5a 100644
--- a/sound/oss/sh_dac_audio.c
+++ b/sound/oss/sh_dac_audio.c
@@ -16,6 +16,7 @@
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/sound.h>
+#include <linux/smp_lock.h>
 #include <linux/soundcard.h>
 #include <linux/interrupt.h>
 #include <linux/hrtimer.h>
@@ -216,13 +217,17 @@ static int dac_audio_open(struct inode *inode, struct file *file)
 {
         if (file->f_mode & FMODE_READ)
                 return -ENODEV;
-        if (in_use)
+
+        lock_kernel();
+        if (in_use) {
+                unlock_kernel();
                 return -EBUSY;
+        }
 
         in_use = 1;
 
         dac_audio_start();
-
+        unlock_kernel();
         return 0;
 }