diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 6e7cdab61827..f71a3dc89048 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -64,6 +64,7 @@ struct rcar_dmac_hw_desc {
  * @chunks: list of transfer chunks for this transfer
  * @running: the transfer chunk being currently processed
  * @nchunks: number of transfer chunks for this transfer
+ * @hwdescs.use: whether the transfer descriptor uses hardware descriptors
  * @hwdescs.mem: hardware descriptors memory for the transfer
  * @hwdescs.dma: device address of the hardware descriptors memory
  * @hwdescs.size: size of the hardware descriptors in bytes
@@ -82,6 +83,7 @@ struct rcar_dmac_desc {
 	unsigned int nchunks;
 
 	struct {
+		bool use;
 		struct rcar_dmac_hw_desc *mem;
 		dma_addr_t dma;
 		size_t size;
@@ -322,7 +324,7 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
 	if (chan->mid_rid >= 0)
 		rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid);
 
-	if (desc->hwdescs.mem) {
+	if (desc->hwdescs.use) {
 		dev_dbg(chan->chan.device->dev,
 			"chan%u: queue desc %p: %u@%pad\n",
 			chan->index, desc, desc->nchunks, &desc->hwdescs.dma);
@@ -480,8 +482,8 @@ static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp)
  * @desc: the descriptor
  *
  * Put the descriptor and its transfer chunk descriptors back in the channel's
- * free descriptors lists, and free the hardware descriptors list memory. The
- * descriptor's chunks list will be reinitialized to an empty list as a result.
+ * free descriptors lists. The descriptor's chunks list will be reinitialized to
+ * an empty list as a result.
  *
  * The descriptor must have been removed from the channel's lists before calling
  * this function.
@@ -491,12 +493,6 @@ static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp)
 static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan,
 			       struct rcar_dmac_desc *desc)
 {
-	if (desc->hwdescs.mem) {
-		dma_free_coherent(NULL, desc->hwdescs.size, desc->hwdescs.mem,
-				  desc->hwdescs.dma);
-		desc->hwdescs.mem = NULL;
-	}
-
 	spin_lock_irq(&chan->lock);
 	list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free);
 	list_add_tail(&desc->node, &chan->desc.free);
@@ -651,20 +647,50 @@ rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan)
 	return chunk;
 }
 
-static void rcar_dmac_alloc_hwdesc(struct rcar_dmac_chan *chan,
-				   struct rcar_dmac_desc *desc)
+static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan,
+				     struct rcar_dmac_desc *desc, size_t size)
+{
+	/*
+	 * dma_alloc_coherent() allocates memory in page size increments. To
+	 * avoid reallocating the hardware descriptors when the allocated size
+	 * wouldn't change align the requested size to a multiple of the page
+	 * size.
+	 */
+	size = PAGE_ALIGN(size);
+
+	if (desc->hwdescs.size == size)
+		return;
+
+	if (desc->hwdescs.mem) {
+		dma_free_coherent(NULL, desc->hwdescs.size, desc->hwdescs.mem,
+				   desc->hwdescs.dma);
+		desc->hwdescs.mem = NULL;
+		desc->hwdescs.size = 0;
+	}
+
+	if (!size)
+		return;
+
+	desc->hwdescs.mem = dma_alloc_coherent(NULL, size, &desc->hwdescs.dma,
+					       GFP_NOWAIT);
+	if (!desc->hwdescs.mem)
+		return;
+
+	desc->hwdescs.size = size;
+}
+
+static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
+				  struct rcar_dmac_desc *desc)
 {
 	struct rcar_dmac_xfer_chunk *chunk;
 	struct rcar_dmac_hw_desc *hwdesc;
-	size_t size = desc->nchunks * sizeof(*hwdesc);
 
-	hwdesc = dma_alloc_coherent(NULL, size, &desc->hwdescs.dma, GFP_NOWAIT);
+	rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc));
+
+	hwdesc = desc->hwdescs.mem;
 	if (!hwdesc)
 		return;
 
-	desc->hwdescs.mem = hwdesc;
-	desc->hwdescs.size = size;
-
 	list_for_each_entry(chunk, &desc->chunks, node) {
 		hwdesc->sar = chunk->src_addr;
 		hwdesc->dar = chunk->dst_addr;
@@ -890,8 +916,9 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
 	 * performance improvement would be significant enough compared to the
 	 * additional complexity remains to be investigated.
 	 */
-	if (!highmem && nchunks > 1)
-		rcar_dmac_alloc_hwdesc(chan, desc);
+	desc->hwdescs.use = !highmem && nchunks > 1;
+	if (desc->hwdescs.use)
+		rcar_dmac_fill_hwdesc(chan, desc);
 
 	return &desc->async_tx;
 }
@@ -930,6 +957,8 @@ static void rcar_dmac_free_chan_resources(struct dma_chan *chan)
 	struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
 	struct rcar_dmac *dmac = to_rcar_dmac(chan->device);
 	struct rcar_dmac_desc_page *page, *_page;
+	struct rcar_dmac_desc *desc;
+	LIST_HEAD(list);
 
 	/* Protect against ISR */
 	spin_lock_irq(&rchan->lock);
@@ -944,6 +973,15 @@ static void rcar_dmac_free_chan_resources(struct dma_chan *chan)
 		rchan->mid_rid = -EINVAL;
 	}
 
+	list_splice(&rchan->desc.free, &list);
+	list_splice(&rchan->desc.pending, &list);
+	list_splice(&rchan->desc.active, &list);
+	list_splice(&rchan->desc.done, &list);
+	list_splice(&rchan->desc.wait, &list);
+
+	list_for_each_entry(desc, &list, node)
+		rcar_dmac_realloc_hwdesc(rchan, desc, 0);
+
 	list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) {
 		list_del(&page->node);
 		free_page((unsigned long)page);
@@ -1114,7 +1152,7 @@ static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan,
 	 * descriptor pointer field in the CHCRB register. In non-descriptor
 	 * mode just use the running descriptor pointer.
 	 */
-	if (desc->hwdescs.mem) {
+	if (desc->hwdescs.use) {
 		dptr = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) &
 			RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT;
 		WARN_ON(dptr >= desc->nchunks);
@@ -1234,7 +1272,7 @@ static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan)
 	 * descriptor mode. Only update the running chunk pointer in
 	 * non-descriptor mode.
 	 */
-	if (!desc->hwdescs.mem) {
+	if (!desc->hwdescs.use) {
 		/*
 		 * If we haven't completed the last transfer chunk simply move
 		 * to the next one. Only wake the IRQ thread if the transfer is