[PATCH v6 1/3] dmaengine: sun6i: Set default maxburst size and bus width

[Jean-Francois Moine]

Some DMA clients, as audio, don't set the maxburst size and bus width
on the memory side when starting DMA transfers.
This patch prevents such transfers to be aborted by providing system
default values to the lacking ones.

Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
---
 drivers/dma/sun6i-dma.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index b08245e..cd436c6 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -470,10 +470,30 @@ static int set_config(struct sun6i_dma_dev *sdev,
 {
 	s8 src_width, dst_width, src_burst, dst_burst;
 
-	src_burst = convert_burst(sconfig->src_maxburst);
-	src_width = convert_buswidth(sconfig->src_addr_width);
-	dst_burst = convert_burst(sconfig->dst_maxburst);
-	dst_width = convert_buswidth(sconfig->dst_addr_width);
+	switch (direction) {
+	case DMA_MEM_TO_DEV:
+		src_burst = convert_burst(sconfig->src_maxburst ?
+					sconfig->src_maxburst : 8);
+		src_width = convert_buswidth(sconfig->src_addr_width !=
+						DMA_SLAVE_BUSWIDTH_UNDEFINED ?
+				sconfig->src_addr_width :
+				DMA_SLAVE_BUSWIDTH_4_BYTES);
+		dst_burst = convert_burst(sconfig->dst_maxburst);
+		dst_width = convert_buswidth(sconfig->dst_addr_width);
+		break;
+	case DMA_DEV_TO_MEM:
+		src_burst = convert_burst(sconfig->src_maxburst);
+		src_width = convert_buswidth(sconfig->src_addr_width);
+		dst_burst = convert_burst(sconfig->dst_maxburst ?
+					sconfig->dst_maxburst : 8);
+		dst_width = convert_buswidth(sconfig->dst_addr_width !=
+						DMA_SLAVE_BUSWIDTH_UNDEFINED ?
+				sconfig->dst_addr_width :
+				DMA_SLAVE_BUSWIDTH_4_BYTES);
+		break;
+	default:
+		return -EINVAL;
+	}
 
 	if (src_burst < 0)
 		return src_burst;
-- 
2.8.1