diff --git a/sys/kern/subr_autoconf.c b/sys/kern/subr_autoconf.c
index 121a18242abe..23416f0010d3 100644
--- a/sys/kern/subr_autoconf.c
+++ b/sys/kern/subr_autoconf.c
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.301 2022/03/28 12:38:59 riastradh Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.302 2022/08/12 16:16:12 riastradh Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.301 2022/03/28 12:38:59 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.302 2022/08/12 16:16:12 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -1919,6 +1919,7 @@ config_dump_garbage(struct devicelist *garbage)
 static int
 config_detach_enter(device_t dev)
 {
+	struct lwp *l __diagused;
 	int error = 0;
 
 	mutex_enter(&config_misc_lock);
@@ -1947,8 +1948,12 @@ config_detach_enter(device_t dev)
 	 * running.  Claim the device for detaching.  This will cause
 	 * all new attempts to acquire references to block.
 	 */
-	KASSERT(dev->dv_attaching == NULL);
-	KASSERT(dev->dv_detaching == NULL);
+	KASSERTMSG((l = dev->dv_attaching) == NULL,
+	    "lwp %ld [%s] @ %p attaching",
+	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l);
+	KASSERTMSG((l = dev->dv_detaching) == NULL,
+	    "lwp %ld [%s] @ %p detaching",
+	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l);
 	dev->dv_detaching = curlwp;
 
 out:	mutex_exit(&config_misc_lock);
@@ -1958,9 +1963,12 @@ out:	mutex_exit(&config_misc_lock);
 static void
 config_detach_exit(device_t dev)
 {
+	struct lwp *l __diagused;
 
 	mutex_enter(&config_misc_lock);
-	KASSERT(dev->dv_detaching == curlwp);
+	KASSERTMSG((l = dev->dv_detaching) == curlwp,
+	    "lwp %ld [%s] @ %p detaching",
+	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l);
 	dev->dv_detaching = NULL;
 	cv_broadcast(&config_misc_cv);
 	mutex_exit(&config_misc_lock);
@@ -2171,9 +2179,12 @@ out:
 void
 config_detach_commit(device_t dev)
 {
+	struct lwp *l __diagused;
 
 	mutex_enter(&config_misc_lock);
-	KASSERT(dev->dv_detaching == curlwp);
+	KASSERTMSG((l = dev->dv_detaching) == curlwp,
+	    "lwp %ld [%s] @ %p detaching",
+	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l);
 	dev->dv_detached = true;
 	cv_broadcast(&config_misc_cv);
 	mutex_exit(&config_misc_lock);