diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index f6d0513..fe9571d 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -43,6 +43,7 @@
 	struct list_head    siblings;   /* list of all devices on this host */
 	struct list_head    same_target_siblings; /* just the devices sharing same target id */
 
+	/* this is now protected by the request_queue->queue_lock */
 	volatile unsigned short device_busy;	/* commands actually active on low-level */
 	spinlock_t list_lock;
 	struct list_head cmd_list;	/* queue of in use SCSI Command structures */