Host component DMA copy the whole copy_bytes.

Host component stops copying bytes at element's end and resumes
copying the remaining bytes in the next round. This leads to jitter
between components of the same pipeline. Such jitter might cause
buffer overwrite for component which processes block by block.

Triggering extra DMA copy until all the copy_bytes are copied can
eliminate the jitter and hence no more buffer overwrite occurs.

Signed-off-by: fy.tsuo <fy.tsuo@intelli-go.com>

Author: fuyuntsuo

src/audio/host.c

@@ -131,6 +131,176 @@ static uint32_t host_dma_get_split(struct host_data *hd, uint32_t bytes)
 	return MAX(split_src, split_dst);
 }
 
+#if CONFIG_FORCE_DMA_COPY_WHOLE_BLOCK
+
+static int host_dma_set_config_and_copy(struct comp_dev *dev, uint32_t bytes)
+{
+	struct host_data *hd = comp_get_drvdata(dev);
+	struct dma_sg_elem *local_elem = hd->config.elem_array.elems;
+	int ret = 0;
+
+	local_elem->size = bytes;
+
+	/* reconfigure transfer */
+	ret = dma_set_config(hd->chan, &hd->config);
+	if (ret < 0) {
+		comp_err(dev, "host_dma_set_config_and_copy(): dma_set_config() failed, ret = %d",
+			 ret);
+		return ret;
+	}
+
+	ret = dma_copy(hd->chan, bytes, DMA_COPY_ONE_SHOT | DMA_COPY_BLOCKING);
+	if (ret < 0) {
+		comp_err(dev, "host_dma_set_config_and_copy(): dma_copy() failed, ret = %d",
+			 ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+/**
+ * Calculates bytes to be copied in one shot mode.
+ * @param dev Host component device.
+ * @return Bytes to be copied.
+ */
+static uint32_t host_get_copy_bytes_one_shot(struct comp_dev *dev)
+{
+	struct host_data *hd = comp_get_drvdata(dev);
+	struct comp_buffer *buffer = hd->local_buffer;
+	uint32_t copy_bytes = 0;
+
+	buffer = buffer_acquire_irq(buffer);
+
+	/* calculate minimum size to copy */
+	if (dev->direction == SOF_IPC_STREAM_PLAYBACK)
+		copy_bytes = audio_stream_get_free_bytes(&buffer->stream);
+	else
+		copy_bytes = audio_stream_get_avail_bytes(&buffer->stream);
+
+	buffer_release_irq(buffer);
+
+	/* copy_bytes should be aligned to minimum possible chunk of
+	 * data to be copied by dma.
+	 */
+	copy_bytes = ALIGN_DOWN(copy_bytes, hd->dma_copy_align);
+
+	return copy_bytes;
+}
+
+/**
+ * Performs copy operation for host component working in one shot mode.
+ * It means DMA needs to be reconfigured after every transfer.
+ * @param dev Host component device.
+ * @return 0 if succeeded, error code otherwise.
+ */
+static int host_copy_one_shot(struct comp_dev *dev)
+{
+	struct host_data *hd = comp_get_drvdata(dev);
+	uint32_t copy_bytes = 0;
+	uint32_t split_value = 0;
+	int ret = 0;
+
+	comp_dbg(dev, "host_copy_one_shot()");
+
+	copy_bytes = host_get_copy_bytes_one_shot(dev);
+	if (!copy_bytes) {
+		comp_info(dev, "host_copy_one_shot(): no bytes to copy");
+		return ret;
+	}
+
+	while (copy_bytes) {
+		/* get split value */
+		split_value = host_dma_get_split(hd, copy_bytes);
+		copy_bytes -= split_value;
+
+		ret = host_dma_set_config_and_copy(dev, copy_bytes);
+		if (ret < 0)
+			return ret;
+
+		/* update copy bytes */
+		copy_bytes = split_value;
+	}
+
+	return ret;
+}
+
+#else /* CONFIG_FORCE_DMA_COPY_WHOLE_BLOCK */
+
+/**
+ * Calculates bytes to be copied in one shot mode.
+ * @param dev Host component device.
+ * @return Bytes to be copied.
+ */
+static uint32_t host_get_copy_bytes_one_shot(struct comp_dev *dev)
+{
+	struct host_data *hd = comp_get_drvdata(dev);
+	struct dma_sg_elem *local_elem = hd->config.elem_array.elems;
+	struct comp_buffer *buffer = hd->local_buffer;
+	uint32_t copy_bytes = 0;
+	uint32_t split_value;
+
+	buffer = buffer_acquire_irq(buffer);
+
+	/* calculate minimum size to copy */
+	if (dev->direction == SOF_IPC_STREAM_PLAYBACK)
+		copy_bytes = audio_stream_get_free_bytes(&buffer->stream);
+	else
+		copy_bytes = audio_stream_get_avail_bytes(&buffer->stream);
+
+	buffer_release_irq(buffer);
+
+	/* copy_bytes should be aligned to minimum possible chunk of
+	 * data to be copied by dma.
+	 */
+	copy_bytes = ALIGN_DOWN(copy_bytes, hd->dma_copy_align);
+
+	split_value = host_dma_get_split(hd, copy_bytes);
+	if (split_value)
+		copy_bytes -= split_value;
+
+	local_elem->size = copy_bytes;
+
+	return copy_bytes;
+}
+
+/**
+ * Performs copy operation for host component working in one shot mode.
+ * It means DMA needs to be reconfigured after every transfer.
+ * @param dev Host component device.
+ * @return 0 if succeeded, error code otherwise.
+ */
+static int host_copy_one_shot(struct comp_dev *dev)
+{
+	struct host_data *hd = comp_get_drvdata(dev);
+	uint32_t copy_bytes = 0;
+	int ret = 0;
+
+	comp_dbg(dev, "host_copy_one_shot()");
+
+	copy_bytes = host_get_copy_bytes_one_shot(dev);
+	if (!copy_bytes) {
+		comp_info(dev, "host_copy_one_shot(): no bytes to copy");
+		return ret;
+	}
+
+	/* reconfigure transfer */
+	ret = dma_set_config(hd->chan, &hd->config);
+	if (ret < 0) {
+		comp_err(dev, "host_copy_one_shot(): dma_set_config() failed, ret = %u", ret);
+		return ret;
+	}
+
+	ret = dma_copy(hd->chan, copy_bytes, DMA_COPY_ONE_SHOT);
+	if (ret < 0) {
+		comp_err(dev, "host_copy_one_shot(): dma_copy() failed, ret = %u", ret);
+		return ret;
+	}
+
+	return ret;
+}
+#endif
+
 static void host_update_position(struct comp_dev *dev, uint32_t bytes)
 {
 	struct host_data *hd = comp_get_drvdata(dev);
@@ -256,79 +426,6 @@ static void host_dma_cb(void *arg, enum notify_id type, void *data)
 		host_one_shot_cb(dev, bytes);
 }
 
-/**
- * Calculates bytes to be copied in one shot mode.
- * @param dev Host component device.
- * @return Bytes to be copied.
- */
-static uint32_t host_get_copy_bytes_one_shot(struct comp_dev *dev)
-{
-	struct host_data *hd = comp_get_drvdata(dev);
-	struct dma_sg_elem *local_elem = hd->config.elem_array.elems;
-	struct comp_buffer *buffer = hd->local_buffer;
-	uint32_t copy_bytes = 0;
-	uint32_t split_value;
-
-	buffer = buffer_acquire_irq(buffer);
-
-	/* calculate minimum size to copy */
-	if (dev->direction == SOF_IPC_STREAM_PLAYBACK)
-		copy_bytes = audio_stream_get_free_bytes(&buffer->stream);
-	else
-		copy_bytes = audio_stream_get_avail_bytes(&buffer->stream);
-
-	buffer_release_irq(buffer);
-
-	/* copy_bytes should be aligned to minimum possible chunk of
-	 * data to be copied by dma.
-	 */
-	copy_bytes = ALIGN_DOWN(copy_bytes, hd->dma_copy_align);
-
-	split_value = host_dma_get_split(hd, copy_bytes);
-	if (split_value)
-		copy_bytes -= split_value;
-
-	local_elem->size = copy_bytes;
-
-	return copy_bytes;
-}
-
-/**
- * Performs copy operation for host component working in one shot mode.
- * It means DMA needs to be reconfigured after every transfer.
- * @param dev Host component device.
- * @return 0 if succeeded, error code otherwise.
- */
-static int host_copy_one_shot(struct comp_dev *dev)
-{
-	struct host_data *hd = comp_get_drvdata(dev);
-	uint32_t copy_bytes = 0;
-	int ret = 0;
-
-	comp_dbg(dev, "host_copy_one_shot()");
-
-	copy_bytes = host_get_copy_bytes_one_shot(dev);
-	if (!copy_bytes) {
-		comp_info(dev, "host_copy_one_shot(): no bytes to copy");
-		return ret;
-	}
-
-	/* reconfigure transfer */
-	ret = dma_set_config(hd->chan, &hd->config);
-	if (ret < 0) {
-		comp_err(dev, "host_copy_one_shot(): dma_set_config() failed, ret = %u", ret);
-		return ret;
-	}
-
-	ret = dma_copy(hd->chan, copy_bytes, DMA_COPY_ONE_SHOT);
-	if (ret < 0) {
-		comp_err(dev, "host_copy_one_shot(): dma_copy() failed, ret = %u", ret);
-		return ret;
-	}
-
-	return ret;
-}
-
 /**
  * Calculates bytes to be copied in normal mode.
  * @param dev Host component device.

src/platform/Kconfig

@@ -499,4 +499,13 @@ config XTENSA_EXCLUSIVE
 	  This has to be selected for xtensa exclusive instructions.
 	  There is a definition for EXCLUSIVE option in xtensa-config.h
 
+config FORCE_DMA_COPY_WHOLE_BLOCK
+	bool
+	default y if MT8195
+	default n
+	depends on HOST_PTABLE
+	help
+	  The host component forces DMA to copy the block size to avoid
+	  copying byte jitter between the components of the same pipeline.
+
 endmenu