1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 77ad192962c5..b82fcd210bf3 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -19,6 +19,7 @@
  *    the userland interface
  */
 
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
@@ -1083,10 +1084,12 @@ static int smu_open(struct inode *inode, struct file *file)
         pp->mode = smu_file_commands;
         init_waitqueue_head(&pp->wait);
 
+        lock_kernel();
         spin_lock_irqsave(&smu_clist_lock, flags);
         list_add(&pp->list, &smu_clist);
         spin_unlock_irqrestore(&smu_clist_lock, flags);
         file->private_data = pp;
+        unlock_kernel();
 
         return 0;
 }