diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 146663c100fd..5cea7d257426 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -539,15 +539,15 @@ static void imx_dma_tx(struct imx_port *sport)
 
 	sport->tx_bytes = uart_circ_chars_pending(xmit);
 
-	if (xmit->tail > xmit->head && xmit->head > 0) {
+	if (xmit->tail < xmit->head) {
+		sport->dma_tx_nents = 1;
+		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
+	} else {
 		sport->dma_tx_nents = 2;
 		sg_init_table(sgl, 2);
 		sg_set_buf(sgl, xmit->buf + xmit->tail,
 				UART_XMIT_SIZE - xmit->tail);
 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
-	} else {
-		sport->dma_tx_nents = 1;
-		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 	}
 
 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);