mod: too quick draining buffer fix

DP may produce a huge chunk of output data (i.e. 10 LL
cycles), and the following module should be able to
consume it in 1 cycle chunks, one by one

unfortunately some modules are not prepared to
work when there's more than 1 data portion available
in the buffer and are draining buffers with data loss

a workaround: copy only the following module's IBS in each LL cycle

required fix: all modules using sink/src interface must be aware to
process only data they need, not forcefully draining a buffer

Signed-off-by: Marcin Szkudlinski <[email protected]>

src/audio/module_adapter/module_adapter.c

@@ -1072,13 +1072,27 @@ static int module_adapter_copy_dp_queues(struct comp_dev *dev)
 	list_for_item(blist, &dev->bsink_list) {
 		/* output - we need to copy data from dp_queue (as source)
 		 * to audio_stream (as sink)
+		 *
+		 * a trick is needed there as a workaround
+		 * DP may produce a huge chunk of output data (i.e. 10 LL
+		 * cycles), and the following module should be able to consume it in 1 cycle chunks
+		 *
+		 * unfortunately some modules are not prepared to work when there's more than
+		 * 1 data portion available in the buffer and are draining buffers with data loss
+		 *
+		 * a workaround: copy only the following module's IBS in each LL cycle
+		 *
+		 * required fix: all modules using sink/src interface must be aware to
+		 * process only data they need, not forcefully draining a buffer
 		 */
 		assert(dp_queue);
 		struct comp_buffer *buffer =
 				container_of(blist, struct comp_buffer, source_list);
 		struct sof_sink *data_sink = audio_stream_get_sink(&buffer->stream);
+		struct sof_source *following_mod_data_source =
+				audio_stream_get_source(&buffer->stream);
 		struct sof_source *data_src = dp_queue_get_source(dp_queue);
-		uint32_t to_copy = MIN(sink_get_free_size(data_sink),
+		uint32_t to_copy = MIN(source_get_min_available(following_mod_data_source),
 				       source_get_data_available(data_src));
 
 		err = source_to_sink_copy(data_src, data_sink, true, to_copy);