diff --git a/sys/dev/mmc/host/dwmmc.c b/sys/dev/mmc/host/dwmmc.c
--- a/sys/dev/mmc/host/dwmmc.c
+++ b/sys/dev/mmc/host/dwmmc.c
@@ -477,33 +477,36 @@
 #ifdef MMCCAM
 	mmc_cam_sim_discover(&sc->mmc_sim);
 #else
+	device_t child;
+	bool present;
+
 	DWMMC_LOCK(sc);
+	child = sc->child;
+	present = READ4(sc, SDMMC_CDETECT) ||
+	    (sc->mmc_helper.props & MMC_PROP_BROKEN_CD) != 0;
+	DWMMC_UNLOCK(sc);
 
-	if (READ4(sc, SDMMC_CDETECT) == 0 ||
-	    (sc->mmc_helper.props & MMC_PROP_BROKEN_CD)) {
-		if (sc->child == NULL) {
-			if (bootverbose)
-				device_printf(sc->dev, "Card inserted\n");
-
-			sc->child = device_add_child(sc->dev, "mmc", DEVICE_UNIT_ANY);
-			DWMMC_UNLOCK(sc);
-			if (sc->child) {
-				device_set_ivars(sc->child, sc);
-				(void)device_probe_and_attach(sc->child);
-			}
-		} else
-			DWMMC_UNLOCK(sc);
-	} else {
-		/* Card isn't present, detach if necessary */
-		if (sc->child != NULL) {
-			if (bootverbose)
-				device_printf(sc->dev, "Card removed\n");
-
-			DWMMC_UNLOCK(sc);
-			device_delete_child(sc->dev, sc->child);
-			sc->child = NULL;
-		} else
-			DWMMC_UNLOCK(sc);
+	if (present && child == NULL) {
+		if (bootverbose)
+			device_printf(sc->dev, "Card inserted\n");
+
+		child = device_add_child(sc->dev, "mmc", DEVICE_UNIT_ANY);
+		if (child != NULL) {
+			device_set_ivars(child, sc);
+			(void)device_probe_and_attach(child);
+		}
+		DWMMC_LOCK(sc);
+		sc->child = child;
+		DWMMC_UNLOCK(sc);
+	} else if (!present && child != NULL) {
+		/* Card isn't present, detach. */
+		if (bootverbose)
+			device_printf(sc->dev, "Card removed\n");
+
+		device_delete_child(sc->dev, child);
+		DWMMC_LOCK(sc);
+		sc->child = NULL;
+		DWMMC_UNLOCK(sc);
 	}
 #endif /* MMCCAM */
 }