pipeline: support concurrent streaming and topology growth

With virtualised clients it can happen, that while one client is
performing audio streaming over a pipeline, another client is adding
components to a new pipeline, that later will be connected to the one
in use. This can happen, e.g. when streaming is taking place on the
host and a guest VM is booting. To support this we need to ignore
newly added but not yet finalised components while traversing
pipelines. Components are in this states after they have been
connected but before the respective pipeline has been finalised, i.e.
before SOF_IPC_TPLG_PIPE_COMPLETE has been issued for it.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

src/audio/pipeline.c

@@ -125,6 +125,13 @@ struct pipeline_walk_context {
 	void *comp_data;
 	void (*buff_func)(struct comp_buffer *, void *);
 	void *buff_data;
+	/*
+	 * If this flag is set, pipeline_for_each_comp() will skip all
+	 * incompletely initialised components, i.e. those, whose .pipeline ==
+	 * NULL. Such coomponents should not be skipped during initialisation
+	 * and clean up, but they should be skipped during streaming.
+	 */
+	bool skip_incomplete;
 };
 
 /* Generic method for walking the graph upstream or downstream.
@@ -150,7 +157,8 @@ static int pipeline_for_each_comp(struct comp_dev *current,
 		buffer_comp = buffer_get_comp(buffer, dir);
 
 		/* don't go further if this component is not connected */
-		if (!buffer_comp)
+		if (!buffer_comp ||
+		    (ctx->skip_incomplete && !buffer_comp->pipeline))
 			continue;
 
 		/* continue further */
@@ -418,12 +426,14 @@ int pipeline_params(struct pipeline *p, struct comp_dev *host,
 	struct pipeline_walk_context hw_param_ctx = {
 		.comp_func = pipeline_comp_hw_params,
 		.comp_data = &data,
+		.skip_incomplete = true,
 	};
 	struct pipeline_walk_context param_ctx = {
 		.comp_func = pipeline_comp_params,
 		.comp_data = &data,
 		.buff_func = pipeline_update_buffer_pcm_params,
 		.buff_data = &params->params,
+		.skip_incomplete = true,
 	};
 	int dir = params->params.direction;
 	int ret;
@@ -557,6 +567,7 @@ int pipeline_prepare(struct pipeline *p, struct comp_dev *dev)
 		.comp_func = pipeline_comp_prepare,
 		.comp_data = &ppl_data,
 		.buff_func = buffer_reset_pos,
+		.skip_incomplete = true,
 	};
 	int ret;
 
@@ -686,6 +697,7 @@ int pipeline_trigger(struct pipeline *p, struct comp_dev *host, int cmd)
 	struct pipeline_walk_context walk_ctx = {
 		.comp_func = pipeline_comp_trigger,
 		.comp_data = &data,
+		.skip_incomplete = true,
 	};
 	int ret;
 
@@ -761,6 +773,7 @@ int pipeline_reset(struct pipeline *p, struct comp_dev *host)
 		.comp_func = pipeline_comp_reset,
 		.comp_data = p,
 		.buff_func = buffer_reset_params,
+		.skip_incomplete = true,
 	};
 	int ret;
 
@@ -824,6 +837,7 @@ static int pipeline_copy(struct pipeline *p)
 	struct pipeline_walk_context walk_ctx = {
 		.comp_func = pipeline_comp_copy,
 		.comp_data = &data,
+		.skip_incomplete = true,
 	};
 	struct comp_dev *start;
 	uint32_t dir;
@@ -881,6 +895,7 @@ void pipeline_get_timestamp(struct pipeline *p, struct comp_dev *host,
 	struct pipeline_walk_context walk_ctx = {
 		.comp_func = pipeline_comp_timestamp,
 		.comp_data = &data,
+		.skip_incomplete = true,
 	};
 
 	platform_host_timestamp(host, posn);
@@ -921,6 +936,7 @@ void pipeline_xrun(struct pipeline *p, struct comp_dev *dev,
 	struct pipeline_walk_context walk_ctx = {
 		.comp_func = pipeline_comp_xrun,
 		.comp_data = &data,
+		.skip_incomplete = true,
 	};
 	struct sof_ipc_stream_posn posn;
 	int ret;