1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index bb93038c48b9..711da01a200b 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -325,6 +325,8 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
                 rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid);
 
         if (desc->hwdescs.use) {
+                struct rcar_dmac_xfer_chunk *chunk;
+
                 dev_dbg(chan->chan.device->dev,
                         "chan%u: queue desc %p: %u@%pad\n",
                         chan->index, desc, desc->nchunks, &desc->hwdescs.dma);
@@ -341,6 +343,18 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
                                      RCAR_DMACHCRB_DRST);
 
                 /*
+                 * Errata: When descriptor memory is accessed through an IOMMU
+                 * the DMADAR register isn't initialized automatically from the
+                 * first descriptor at beginning of transfer by the DMAC like it
+                 * should. Initialize it manually with the destination address
+                 * of the first chunk.
+                 */
+                chunk = list_first_entry(&desc->chunks,
+                                         struct rcar_dmac_xfer_chunk, node);
+                rcar_dmac_chan_write(chan, RCAR_DMADAR,
+                                     chunk->dst_addr & 0xffffffff);
+
+                /*
                  * Program the descriptor stage interrupt to occur after the end
                  * of the first stage.
                  */