[PATCH v2 01/14] dmaengine: edma: Remove alignment constraint for memcpy

Peter Ujfalusi
2015-10-16T07:24:53Z

Despite the claim by the original commit adding the memcpy
support, eDMA does not have constraint on the alignment of src, dst
or length in increment mode.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
drivers/dma/edma.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 7eefbf1e1c94..b36dfa5458cb 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -1324,6 +1324,7 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
struct edma_desc *edesc;
struct device *dev = chan->device->dev;
struct edma_chan *echan = to_edma_chan(chan);
+ unsigned int width;

if (unlikely(!echan || !len))
return NULL;
@@ -1336,8 +1337,12 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(

edesc->pset_nr = 1;

+ width = 1 << __ffs((src | dest | len));
+ if (width > DMA_SLAVE_BUSWIDTH_64_BYTES)
+ width = DMA_SLAVE_BUSWIDTH_64_BYTES;
+
ret = edma_config_pset(chan, &edesc->pset[0], src, dest, 1,
- DMA_SLAVE_BUSWIDTH_4_BYTES, len, DMA_MEM_TO_MEM);
+ width, len, DMA_MEM_TO_MEM);
if (ret < 0)
return NULL;

@@ -1903,12 +1908,6 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,

dma->dev = dev;

- /*
- * code using dma memcpy must make sure alignment of
- * length is at dma->copy_align boundary.
- */
- dma->copy_align = DMAENGINE_ALIGN_4_BYTES;
-
INIT_LIST_HEAD(&dma->channels);
}

--
2.6.1