diff -ruN a/sys/dev/raid/dpt/dpt_pci.c b/sys/dev/raid/dpt/dpt_pci.c
--- a/sys/dev/raid/dpt/dpt_pci.c	2026-09-30 12:02:43.968772172 +0000
+++ b/sys/dev/raid/dpt/dpt_pci.c	2026-09-30 12:02:43.980772017 +0000
@@ -150,6 +150,8 @@
 
 	if (dpt_init(dpt) != 0) {
 		dpt_free(dpt);
+		/* parent_dmat is created by this glue, not by dpt_init() */
+		bus_dma_tag_destroy(dpt->parent_dmat);
 		error = ENXIO;
 		crit_exit();
 		goto bad;