dmaengine: at_xdmac: change block increment addressing mode

The addressing mode we were using was not only incrementing the address at
each microblock, but also at each data boundary, which was severely slowing
the transfer, without any benefit since we were not using the data stride.

Switch to the micro block increment only in order to get back to an
acceptable performance level.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: 6007ccb57744 ("dmaengine: xdmac: Add interleaved transfer support")
Cc: stable@vger.kernel.org #4.2
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index a165b4bfd3300e97d409f2053b71adb276392336..ffea6027b631982d0fedc973e890910c15685aa6 100644 (file)
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -875,14 +875,14 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan,
 
        if (xt->src_inc) {
                if (xt->src_sgl)
-                       chan_cc |=  AT_XDMAC_CC_SAM_UBS_DS_AM;
+                       chan_cc |=  AT_XDMAC_CC_SAM_UBS_AM;
                else
                        chan_cc |=  AT_XDMAC_CC_SAM_INCREMENTED_AM;
        }
 
        if (xt->dst_inc) {
                if (xt->dst_sgl)
-                       chan_cc |=  AT_XDMAC_CC_DAM_UBS_DS_AM;
+                       chan_cc |=  AT_XDMAC_CC_DAM_UBS_AM;
                else
                        chan_cc |=  AT_XDMAC_CC_DAM_INCREMENTED_AM;
        }