Index: sys/dev/sdhci/sdhci.c
===================================================================
--- sys/dev/sdhci/sdhci.c
+++ sys/dev/sdhci/sdhci.c
@@ -185,15 +185,20 @@
 static int
 slot_printf(const struct sdhci_slot *slot, const char * fmt, ...)
 {
+	char buf[MAX_INPUT];
 	va_list ap;
 	int retval;
 
-	retval = printf("%s-slot%d: ",
-	    device_get_nameunit(slot->bus), slot->num);
-
+	/*
+	 * Make sure we print a single line all together rather than in two
+	 * halves to avoid console gibberish bingo.
+	 */
 	va_start(ap, fmt);
-	retval += vprintf(fmt, ap);
+	retval = vsnprintf(buf, sizeof(buf), fmt, ap);
 	va_end(ap);
+
+	retval += printf("%s-slot%d: %s",
+	    device_get_nameunit(slot->bus), slot->num, buf);
 	return (retval);
 }