[Sound-open-firmware] [PATCH] host: remove first_copy workaround for HDA DMA

[Keyon Jie]

Here remove the first_copy workaround(it was needed as HDA DMA is not
available at the trigger start stage).

This require the fix from host driver side:
ASoC: SOF: hw-apl: start HDA DMA at stream_prepare() stage and remove
stream_trigger()

Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
---
Test with:
Mininow max rt5651 and APL GPMRB and CNL nocodec
SOF master: 7c5dd8cfdf4f8ca1fa5cfdd7352b81cbfc8edb88
SOF-Tool master: 86fe688a2b4f68a1ce87e0951686be12a00f1a3c
https://github.com/plbossart/sound/tree/topic/sof-v4.14:
22c8b2b68186e6af83f21c302d8086559b5d2e23

note: this need be merged with driver patch together:
'ASoC: SOF: start HDA DMA at hw_params() stage and remove stream_trigger()'

---
 src/audio/host.c | 41 ++++++++++++-----------------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/src/audio/host.c b/src/audio/host.c
index 998c5ca..a0956b3 100644
--- a/src/audio/host.c
+++ b/src/audio/host.c
@@ -84,9 +84,6 @@ struct host_data {
 	uint32_t period_bytes;
 	uint32_t period_count;
 
-#if defined CONFIG_DMA_GW
-	uint32_t first_copy;
-#endif
 	/* stream info */
 	struct sof_ipc_stream_posn posn; /* TODO: update this */
 };
@@ -477,12 +474,12 @@ static int host_trigger(struct comp_dev *dev, int cmd)
 			goto out;
 		}
 
-		/* preload first playback period for preloader task */
+		/*
+		 * host dma will copy the first period once it is started,
+		 * automatically.
+		 * Here update the pointers to reflect the real case.
+		 */
 		if (dev->params.direction == SOF_IPC_STREAM_PLAYBACK) {
-			/*
-			 * host dma will not start copy at this point yet,
-			 * just produce empty period bytes for it.
-			 */
 			comp_update_buffer_produce(hd->dma_buffer,
 						   hd->period_bytes);
 		}
@@ -736,10 +733,6 @@ static int host_prepare(struct comp_dev *dev)
 	hd->split_remaining = 0;
 	dev->position = 0;
 
-#if defined CONFIG_DMA_GW
-	hd->first_copy = 1;
-#endif
-
 	return 0;
 }
 
@@ -863,19 +856,6 @@ static int host_copy(struct comp_dev *dev)
 	if (dev->state != COMP_STATE_ACTIVE)
 		return 0;
 
-#if defined CONFIG_DMA_GW
-	if (dev->params.direction == SOF_IPC_STREAM_PLAYBACK &&
-	    hd->first_copy) {
-		/*
-		 * host dma will not start copy at this point yet, just produce
-		 * empty period bytes for it.
-		 */
-		comp_update_buffer_produce(hd->dma_buffer,
-					   hd->period_bytes);
-		hd->first_copy = 0;
-		return 0;
-	}
-#endif
 	local_elem = list_first_item(&hd->config.elem_list,
 		struct dma_sg_elem, list);
 
@@ -896,14 +876,17 @@ static int host_copy(struct comp_dev *dev)
 	}
 
 #if defined CONFIG_DMA_GW
-
-	/* update host pointers from last period */
-	host_gw_dma_update(dev);
-
 	/* tell gateway to copy another period */
 	ret = dma_copy(hd->dma, hd->chan, hd->period_bytes);
 	if (ret < 0)
 		goto out;
+
+	/*
+	 * update host pointers for the new copied period.
+	 * fixme: do we need wait and check to make sure
+	 * the new copy is finished here?
+	 */
+	host_gw_dma_update(dev);
 #else
 	/* do DMA transfer */
 	ret = dma_set_config(hd->dma, hd->chan, &hd->config);
-- 
2.14.1