Index: sys/cam/nvme/nvme_da.c
===================================================================
--- sys/cam/nvme/nvme_da.c
+++ sys/cam/nvme/nvme_da.c
@@ -1059,6 +1059,8 @@
 			cam_iosched_bio_complete(softc->cam_iosched, bp, done_ccb);
 			xpt_release_ccb(done_ccb);
 			ndaschedule(periph);
+			KASSERT(softc->refcount >= 1, ("ndadone softc %p refcount %d", softc, softc->refcount));
+			softc->refcount--; /* Release the periph refcount taken in mdastart() for each CCB. *.
 			cam_periph_unlock(periph);
 			biodone(bp);
 		} else { /* state == NDA_CCB_TRIM */
@@ -1086,6 +1088,8 @@
 			cam_iosched_bio_complete(softc->cam_iosched, bp1, done_ccb);
 			xpt_release_ccb(done_ccb);
 			ndaschedule(periph);
+			KASSERT(softc->refcount >= 1, ("ndadone softc %p refcount %d", softc, softc->refcount));
+			softc->refcount--; /* Release the periph refcount taken in mdastart() for each CCB. *.
 			cam_periph_unlock(periph);
 			while ((bp2 = TAILQ_FIRST(&queue)) != NULL) {
 				TAILQ_REMOVE(&queue, bp2, bio_queue);
@@ -1100,11 +1104,6 @@
 				biodone(bp2);
 			}
 		}
-		/*
-		 * Release the periph refcount taken in mdastart() for each CCB.
-		 */
-		KASSERT(softc->refcount >= 1, ("ndadone softc %p refcount %d", softc, softc->refcount));
-		softc->refcount--;
 		return;
 	}
 	case NDA_CCB_DUMP: