[RFC PATCH 6/6] ASoC: dmaengine: Allocate buffer if substream is unmanaged

[Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>]

pcm_construct/pcm_destruct callbacks are not called for BE DAIs. This means
that, if the generic dmaengine driver is used, there is no managed buffer
allocation (or pre-allocation). To be able to use the generic dmaengine
driver for BE DAI links, allocate the buffer in the hw_params callback if
there is no managed buffer.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
---
 sound/soc/soc-generic-dmaengine-pcm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 9ef80a48707e..c915da71e1cd 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -98,6 +98,22 @@ static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
 			return ret;
 	}
 
+	if (!substream->managed_buffer_alloc) {
+		substream->dma_buffer.dev.type = SNDRV_DMA_TYPE_DEV_IRAM;
+		substream->dma_buffer.dev.dev = chan->device->dev;
+		return snd_pcm_lib_malloc_pages(substream,
+						params_buffer_bytes(params));
+	}
+
+	return 0;
+}
+
+static int dmaengine_pcm_hw_free(struct snd_soc_component *component,
+				 struct snd_pcm_substream *substream)
+{
+	if (!substream->managed_buffer_alloc)
+		return snd_pcm_lib_free_pages(substream);
+
 	return 0;
 }
 
@@ -332,6 +348,7 @@ static const struct snd_soc_component_driver dmaengine_pcm_component = {
 	.open		= dmaengine_pcm_open,
 	.close		= dmaengine_pcm_close,
 	.hw_params	= dmaengine_pcm_hw_params,
+	.hw_free	= dmaengine_pcm_hw_free,
 	.trigger	= dmaengine_pcm_trigger,
 	.pointer	= dmaengine_pcm_pointer,
 	.pcm_construct	= dmaengine_pcm_new,
@@ -343,6 +360,7 @@ static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
 	.open		= dmaengine_pcm_open,
 	.close		= dmaengine_pcm_close,
 	.hw_params	= dmaengine_pcm_hw_params,
+	.hw_free	= dmaengine_pcm_hw_free,
 	.trigger	= dmaengine_pcm_trigger,
 	.pointer	= dmaengine_pcm_pointer,
 	.copy_user	= dmaengine_copy_user,
-- 
2.27.0