diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index f7397789e4e8..b579bac56383 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -295,6 +295,39 @@ static inline struct pl08x_txd *to_pl08x_txd(struct dma_async_tx_descriptor *tx)
 	return container_of(tx, struct pl08x_txd, tx);
 }
 
+/*
+ * Mux handling.
+ *
+ * This gives us the DMA request input to the PL08x primecell which the
+ * peripheral described by the channel data will be routed to, possibly
+ * via a board/SoC specific external MUX.  One important point to note
+ * here is that this does not depend on the physical channel.
+ */
+static int pl08x_request_mux(struct pl08x_dma_chan *plchan, struct pl08x_phy_chan *ch)
+{
+	const struct pl08x_platform_data *pd = plchan->host->pd;
+	int ret;
+
+	if (pd->get_signal) {
+		ret = pd->get_signal(plchan->cd);
+		if (ret < 0)
+			return ret;
+
+		ch->signal = ret;
+	}
+	return 0;
+}
+
+static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
+{
+	const struct pl08x_platform_data *pd = plchan->host->pd;
+
+	if (plchan->phychan->signal >= 0 && pd->put_signal) {
+		pd->put_signal(plchan->cd, plchan->phychan->signal);
+		plchan->phychan->signal = -1;
+	}
+}
+
 /*
  * Physical channel handling
  */
@@ -999,8 +1032,8 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 	 * need, but for slaves the physical signals may be muxed!
 	 * Can the platform allow us to use this channel?
 	 */
-	if (plchan->slave && pl08x->pd->get_signal) {
-		ret = pl08x->pd->get_signal(plchan->cd);
+	if (plchan->slave) {
+		ret = pl08x_request_mux(plchan, ch);
 		if (ret < 0) {
 			dev_dbg(&pl08x->adev->dev,
 				"unable to use physical channel %d for transfer on %s due to platform restrictions\n",
@@ -1009,7 +1042,6 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 			pl08x_put_phy_channel(pl08x, ch);
 			return -EBUSY;
 		}
-		ch->signal = ret;
 	}
 
 	plchan->phychan = ch;
@@ -1034,10 +1066,7 @@ static void release_phy_channel(struct pl08x_dma_chan *plchan)
 {
 	struct pl08x_driver_data *pl08x = plchan->host;
 
-	if ((plchan->phychan->signal >= 0) && pl08x->pd->put_signal) {
-		pl08x->pd->put_signal(plchan->cd, plchan->phychan->signal);
-		plchan->phychan->signal = -1;
-	}
+	pl08x_release_mux(plchan);
 	pl08x_put_phy_channel(pl08x, plchan->phychan);
 	plchan->phychan = NULL;
 }