Index: sys/dev/ata/ata-dma.c
===================================================================
--- sys/dev/ata/ata-dma.c	(revision 266867)
+++ sys/dev/ata/ata-dma.c	(working copy)
@@ -224,9 +224,8 @@ ata_dmafree(device_t dev)
             bus_dmamap_unload(slot->sg_tag, slot->sg_map);
             slot->sg_bus = 0;
 	}
-	if (slot->sg_map) {
+	if (slot->sg != NULL) {
             bus_dmamem_free(slot->sg_tag, slot->sg, slot->sg_map);
-            bus_dmamap_destroy(slot->sg_tag, slot->sg_map);
             slot->sg = NULL;
             slot->sg_map = NULL;
 	}