[alsa-devel] [PATCH v2 03/15] dmaengine: Add no_wakeup parameter to dmaengine_prep_dma_cyclic()

Peter Ujfalusi peter.ujfalusi at ti.com
Thu Sep 13 15:37:53 CEST 2012

The dmaengine_prep_dma_cyclic() function primarily used by audio for cyclic
transfer required by ALSA.
With this new parameter it is going to be possible to enable the
SNDRV_PCM_INFO_NO_PERIOD_WAKEUP mode on platforms where it is possible.
This patch only changes the public API first. Followup patch will change
the device_prep_dma_cyclic() callback parameters to pass this information
towards the dma drivers.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
CC: Lars-Peter Clausen <lars at metafoo.de>
 include/linux/dmaengine.h     | 3 ++-
 sound/soc/soc-dmaengine-pcm.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 9c02a45..990444b 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -653,7 +653,8 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg(
 static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(
 		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
-		size_t period_len, enum dma_transfer_direction dir)
+		size_t period_len, enum dma_transfer_direction dir,
+		bool no_wakeup)
 	return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
 						period_len, dir, NULL);
diff --git a/sound/soc/soc-dmaengine-pcm.c b/sound/soc/soc-dmaengine-pcm.c
index 5df529e..6b70adb 100644
--- a/sound/soc/soc-dmaengine-pcm.c
+++ b/sound/soc/soc-dmaengine-pcm.c
@@ -147,7 +147,8 @@ static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 	desc = dmaengine_prep_dma_cyclic(chan,
-		snd_pcm_lib_period_bytes(substream), direction);
+		snd_pcm_lib_period_bytes(substream), direction,
+		substream->runtime->no_period_wakeup);
 	if (!desc)
 		return -ENOMEM;

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