[alsa-devel] [RFC update 1/2] dmaengine: omap: Support for element mode in cyclic DMA

Peter Ujfalusi peter.ujfalusi at ti.com
Tue Sep 4 14:08:01 CEST 2012


When src_maxburst/dst_maxburst is set to 0 by the users of cyclic DMA
(mostly audio) indicates that we should configure the omap DMA to element
sync mode instead of packet mode.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
---
 drivers/dma/omap-dma.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index ae05618..b77a40d 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -413,7 +413,10 @@ static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
 	d->dev_addr = dev_addr;
 	d->fi = burst;
 	d->es = es;
-	d->sync_mode = OMAP_DMA_SYNC_PACKET;
+	if (burst)
+		d->sync_mode = OMAP_DMA_SYNC_PACKET;
+	else
+		d->sync_mode = OMAP_DMA_SYNC_ELEMENT;
 	d->sync_type = sync_type;
 	d->periph_port = OMAP_DMA_PORT_MPUI;
 	d->sg[0].addr = buf_addr;
-- 
1.7.12



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