macintosh-smu: BKL pushdown

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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;
 }