[Sound-open-firmware] [RFC/RFT] dai: Make system stable by moving DAI buffer pointer update location

[Keyon Jie]

From: Wu Zhigang <zhigang.wu at linux.intel.com>

Move the DAI's buffer pointer update location from dai_dma_cb()
to dai_copy(). This will make pipeline more stable. The xrun possibility
will be lower.Even in xrun it will recover, it will not have dsp oops.
DAI's buffer pointer will be updated in the pipeline copy sequence
as other components did. Then the DMA will not update the buffer pointer
by itself. in HOST--->VOL--->DAI pipeline, when DMA finished, it has to
reschedule the pipeline to let the pointer update. this could avoid
the xrun when adjust the read and write pointers by different componets.

Signed-off-by: Wu Zhigang <zhigang.wu at linux.intel.com>
Tested-by: Keyon Jie <yang.jie at linux.intel.com>
---
Tested on APL-GPMRB
kernel: sof-v4.14   commit <c33cfed51fff5eb156dcf70ba849e6ffb3008377>
sof:    1.1-stable  commit <949de92142aa9cdd4a31fda68f05d29212683cc1>
tools:  1.1-stable  commit <b799e3fa3bab7f5df70f2458bda42de167e65fb3>

RFT: can someone help test it on byt also?

 src/audio/dai.c | 108 +++++++++++++++++++++++++++++---------------------------
 1 file changed, 56 insertions(+), 52 deletions(-)

diff --git a/src/audio/dai.c b/src/audio/dai.c
index e1ea9ab..6d0c1fa 100644
--- a/src/audio/dai.c
+++ b/src/audio/dai.c
@@ -78,7 +78,6 @@ static void dai_dma_cb(void *data, uint32_t type, struct dma_sg_elem *next)
 	struct comp_dev *dev = (struct comp_dev *)data;
 	struct dai_data *dd = comp_get_drvdata(dev);
 	struct comp_buffer *dma_buffer;
-	uint32_t copied_size;
 
 	trace_dai("irq");
 
@@ -114,57 +113,6 @@ static void dai_dma_cb(void *data, uint32_t type, struct dma_sg_elem *next)
 		return;
 	}
 
-	if (dev->params.direction == SOF_IPC_STREAM_PLAYBACK) {
-		dma_buffer = list_first_item(&dev->bsource_list,
-			struct comp_buffer, sink_list);
-
-		copied_size = dd->last_bytes ? dd->last_bytes : dd->period_bytes;
-
-		/* recalc available buffer space */
-		comp_update_buffer_consume(dma_buffer, copied_size);
-
-		/* writeback buffer contents from cache */
-		dcache_writeback_region(dma_buffer->r_ptr, copied_size);
-
-		/* update host position(in bytes offset) for drivers */
-		dev->position += copied_size;
-		if (dd->dai_pos) {
-			dd->dai_pos_blks += copied_size;
-			*dd->dai_pos = dd->dai_pos_blks +
-				dma_buffer->r_ptr - dma_buffer->addr;
-		}
-
-		/* make sure there is availble bytes for next period */
-		if (dma_buffer->avail < dd->period_bytes) {
-			trace_dai_error("xru");
-			comp_underrun(dev, dma_buffer, copied_size, 0);
-		}
-
-	} else {
-		dma_buffer = list_first_item(&dev->bsink_list,
-			struct comp_buffer, source_list);
-
-		/* invalidate buffer contents */
-		dcache_invalidate_region(dma_buffer->w_ptr, dd->period_bytes);
-
-		/* recalc available buffer space */
-		comp_update_buffer_produce(dma_buffer, dd->period_bytes);
-
-		/* update positions */
-		dev->position += dd->period_bytes;
-		if (dd->dai_pos) {
-			dd->dai_pos_blks += dd->period_bytes;
-			*dd->dai_pos = dd->dai_pos_blks +
-				dma_buffer->w_ptr - dma_buffer->addr;
-		}
-
-		/* make sure there is free bytes for next period */
-		if (dma_buffer->free < dd->period_bytes) {
-			trace_dai_error("xro");
-			comp_overrun(dev, dma_buffer, dd->period_bytes, 0);
-		}
-	}
-
 	/* notify pipeline that DAI needs its buffer processed */
 	if (dev->state == COMP_STATE_ACTIVE)
 		pipeline_schedule_copy(dev->pipeline, 0);
@@ -607,6 +555,62 @@ static int dai_comp_trigger(struct comp_dev *dev, int cmd)
 /* copy and process stream data from source to sink buffers */
 static int dai_copy(struct comp_dev *dev)
 {
+	struct dai_data *dd = comp_get_drvdata(dev);
+	struct comp_buffer *dma_buffer;
+	uint32_t copied_size;
+
+	if (dev->params.direction == SOF_IPC_STREAM_PLAYBACK) {
+		dma_buffer = list_first_item(&dev->bsource_list,
+					     struct comp_buffer, sink_list);
+
+		copied_size = dd->last_bytes ?
+			dd->last_bytes : dd->period_bytes;
+
+		/* recalc available buffer space */
+		comp_update_buffer_consume(dma_buffer, copied_size);
+
+		/* writeback buffer contents from cache */
+		dcache_writeback_region(dma_buffer->r_ptr, copied_size);
+
+		/* update host position(in bytes offset) for drivers */
+		dev->position += copied_size;
+		if (dd->dai_pos) {
+			dd->dai_pos_blks += copied_size;
+			*dd->dai_pos = dd->dai_pos_blks +
+				dma_buffer->r_ptr - dma_buffer->addr;
+		}
+
+		/* make sure there is available bytes for next period */
+		if (dma_buffer->avail < dd->period_bytes) {
+			trace_dai_error("xru");
+			comp_underrun(dev, dma_buffer, copied_size, 0);
+		}
+
+	} else {
+		dma_buffer = list_first_item(&dev->bsink_list,
+					     struct comp_buffer, source_list);
+
+		/* invalidate buffer contents */
+		dcache_invalidate_region(dma_buffer->w_ptr, dd->period_bytes);
+
+		/* recalc available buffer space */
+		comp_update_buffer_produce(dma_buffer, dd->period_bytes);
+
+		/* update positions */
+		dev->position += dd->period_bytes;
+		if (dd->dai_pos) {
+			dd->dai_pos_blks += dd->period_bytes;
+			*dd->dai_pos = dd->dai_pos_blks +
+				dma_buffer->w_ptr - dma_buffer->addr;
+		}
+
+		/* make sure there is free bytes for next period */
+		if (dma_buffer->free < dd->period_bytes) {
+			trace_dai_error("xro");
+			comp_overrun(dev, dma_buffer, dd->period_bytes, 0);
+		}
+	}
+
 	return 0;
 }
 
-- 
2.14.1