[PATCH 4.2.y-ckt 197/305] dmaengine: at_xdmac: fix at_xdmac_prep_dma_memcpy()

[Kamal Mostafa]

4.2.8-ckt2 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Cyrille Pitchen <cyrille.pitchen at atmel.com>

commit aa876cd4b41b4e3bcfbc75dd5750d75d5fa97a67 upstream.

This patch fixes at_xdmac_prep_dma_memcpy(). Indeed the data width field
of the Channel Configuration register was not updated properly in the
loop: the bits of the dwidth field were not cleared before adding their
new value.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
Acked-by: Ludovic Desroches <ludovic.desroches at atmel.com>
Fixes: e1f7c9eee70 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/dma/at_xdmac.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 2205def..c01cdec 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1086,6 +1086,7 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		/* Check remaining length and change data width if needed. */
 		dwidth = at_xdmac_align_width(chan,
 					      src_addr | dst_addr | xfer_size);
+		chan_cc &= ~AT_XDMAC_CC_DWIDTH_MASK;
 		chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
 
 		ublen = xfer_size >> dwidth;
-- 
1.9.1