diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index ab7ee44..ac0e3e4 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -312,11 +312,20 @@
 	if (t->bits_per_word)
 		bits_per_word = t->bits_per_word;
 	len = t->len;
-	if (bits_per_word > 8)
+	if (bits_per_word > 8) {
+		/* invalid length? */
+		if (len & 1)
+			return -EINVAL;
 		len /= 2;
-	if (bits_per_word > 16)
+	}
+	if (bits_per_word > 16) {
+		/* invalid length? */
+		if (len & 1)
+			return -EINVAL;
 		len /= 2;
+	}
 	mpc83xx_spi->count = len;
+
 	INIT_COMPLETION(mpc83xx_spi->done);
 
 	/* enable rx ints */