diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 3c55600a8236..c5c891c8714e 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -135,6 +135,8 @@ struct sci_port {
 	struct dma_chan			*chan_rx;
 
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
+	struct dma_chan			*chan_tx_saved;
+	struct dma_chan			*chan_rx_saved;
 	dma_cookie_t			cookie_tx;
 	dma_cookie_t			cookie_rx[2];
 	dma_cookie_t			active_rx;
@@ -1212,25 +1214,16 @@ static int sci_dma_rx_find_active(struct sci_port *s)
 	return -1;
 }
 
-static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
+static void sci_rx_dma_release(struct sci_port *s)
 {
-	struct dma_chan *chan = s->chan_rx;
-	struct uart_port *port = &s->port;
-	unsigned long flags;
+	struct dma_chan *chan = s->chan_rx_saved;
 
-	spin_lock_irqsave(&port->lock, flags);
-	s->chan_rx = NULL;
+	s->chan_rx_saved = s->chan_rx = NULL;
 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
-	spin_unlock_irqrestore(&port->lock, flags);
 	dmaengine_terminate_all(chan);
 	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
 			  sg_dma_address(&s->sg_rx[0]));
 	dma_release_channel(chan);
-	if (enable_pio) {
-		spin_lock_irqsave(&port->lock, flags);
-		sci_start_rx(port);
-		spin_unlock_irqrestore(&port->lock, flags);
-	}
 }
 
 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
@@ -1289,33 +1282,30 @@ static void sci_dma_rx_complete(void *arg)
 fail:
 	spin_unlock_irqrestore(&port->lock, flags);
 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
-	sci_rx_dma_release(s, true);
+	/* Switch to PIO */
+	spin_lock_irqsave(&port->lock, flags);
+	s->chan_rx = NULL;
+	sci_start_rx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
+static void sci_tx_dma_release(struct sci_port *s)
 {
-	struct dma_chan *chan = s->chan_tx;
-	struct uart_port *port = &s->port;
-	unsigned long flags;
+	struct dma_chan *chan = s->chan_tx_saved;
 
-	spin_lock_irqsave(&port->lock, flags);
-	s->chan_tx = NULL;
+	s->chan_tx_saved = s->chan_tx = NULL;
 	s->cookie_tx = -EINVAL;
-	spin_unlock_irqrestore(&port->lock, flags);
 	dmaengine_terminate_all(chan);
 	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
 			 DMA_TO_DEVICE);
 	dma_release_channel(chan);
-	if (enable_pio) {
-		spin_lock_irqsave(&port->lock, flags);
-		sci_start_tx(port);
-		spin_unlock_irqrestore(&port->lock, flags);
-	}
 }
 
 static void sci_submit_rx(struct sci_port *s)
 {
 	struct dma_chan *chan = s->chan_rx;
+	struct uart_port *port = &s->port;
+	unsigned long flags;
 	int i;
 
 	for (i = 0; i < 2; i++) {
@@ -1347,7 +1337,11 @@ fail:
 	for (i = 0; i < 2; i++)
 		s->cookie_rx[i] = -EINVAL;
 	s->active_rx = -EINVAL;
-	sci_rx_dma_release(s, true);
+	/* Switch to PIO */
+	spin_lock_irqsave(&port->lock, flags);
+	s->chan_rx = NULL;
+	sci_start_rx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static void work_fn_tx(struct work_struct *work)
@@ -1357,6 +1351,7 @@ static void work_fn_tx(struct work_struct *work)
 	struct dma_chan *chan = s->chan_tx;
 	struct uart_port *port = &s->port;
 	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
 	dma_addr_t buf;
 
 	/*
@@ -1378,9 +1373,7 @@ static void work_fn_tx(struct work_struct *work)
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
-		/* switch to PIO */
-		sci_tx_dma_release(s, true);
-		return;
+		goto switch_to_pio;
 	}
 
 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
@@ -1393,15 +1386,21 @@ static void work_fn_tx(struct work_struct *work)
 	s->cookie_tx = dmaengine_submit(desc);
 	if (dma_submit_error(s->cookie_tx)) {
 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
-		/* switch to PIO */
-		sci_tx_dma_release(s, true);
-		return;
+		goto switch_to_pio;
 	}
 
 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
 		__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
 
 	dma_async_issue_pending(chan);
+	return;
+
+switch_to_pio:
+	spin_lock_irqsave(&port->lock, flags);
+	s->chan_tx = NULL;
+	sci_start_tx(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return;
 }
 
 static enum hrtimer_restart rx_timer_fn(struct hrtimer *t)
@@ -1535,7 +1534,6 @@ static void sci_request_dma(struct uart_port *port)
 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
 	if (chan) {
-		s->chan_tx = chan;
 		/* UART circular tx buffer is an aligned page. */
 		s->tx_dma_addr = dma_map_single(chan->device->dev,
 						port->state->xmit.buf,
@@ -1544,11 +1542,13 @@ static void sci_request_dma(struct uart_port *port)
 		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
 			dma_release_channel(chan);
-			s->chan_tx = NULL;
+			chan = NULL;
 		} else {
 			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
 				__func__, UART_XMIT_SIZE,
 				port->state->xmit.buf, &s->tx_dma_addr);
+
+			s->chan_tx_saved = s->chan_tx = chan;
 		}
 
 		INIT_WORK(&s->work_tx, work_fn_tx);
@@ -1561,8 +1561,6 @@ static void sci_request_dma(struct uart_port *port)
 		dma_addr_t dma;
 		void *buf;
 
-		s->chan_rx = chan;
-
 		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
 		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
 					 &dma, GFP_KERNEL);
@@ -1570,7 +1568,6 @@ static void sci_request_dma(struct uart_port *port)
 			dev_warn(port->dev,
 				 "Failed to allocate Rx dma buffer, using PIO\n");
 			dma_release_channel(chan);
-			s->chan_rx = NULL;
 			return;
 		}
 
@@ -1591,6 +1588,8 @@ static void sci_request_dma(struct uart_port *port)
 
 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 			sci_submit_rx(s);
+
+		s->chan_rx_saved = s->chan_rx = chan;
 	}
 }
 
@@ -1598,10 +1597,10 @@ static void sci_free_dma(struct uart_port *port)
 {
 	struct sci_port *s = to_sci_port(port);
 
-	if (s->chan_tx)
-		sci_tx_dma_release(s, false);
-	if (s->chan_rx)
-		sci_rx_dma_release(s, false);
+	if (s->chan_tx_saved)
+		sci_tx_dma_release(s);
+	if (s->chan_rx_saved)
+		sci_rx_dma_release(s);
 }
 
 static void sci_flush_buffer(struct uart_port *port)
@@ -2092,7 +2091,7 @@ static void sci_shutdown(struct uart_port *port)
 	spin_unlock_irqrestore(&port->lock, flags);
 
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
-	if (s->chan_rx) {
+	if (s->chan_rx_saved) {
 		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
 			port->line);
 		hrtimer_cancel(&s->rx_timer);