diff --git a/include/linux/ata.h b/include/linux/ata.h
index d2992bf..c1a2f34 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -487,8 +487,8 @@
 };
 
 enum ata_ioctls {
-	ATA_IOC_GET_IO32	= 0x309,
-	ATA_IOC_SET_IO32	= 0x324,
+	ATA_IOC_GET_IO32	= 0x309, /* HDIO_GET_32BIT */
+	ATA_IOC_SET_IO32	= 0x324, /* HDIO_SET_32BIT */
 };
 
 /* core structures */