diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/sh/rcar-dmac.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index bb93038..711da01 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. */ |