[PATCH v4 09/26] ASoC: SOF: sof-audio: Fix the pipeline_list population

[Peter Ujfalusi <peter.ujfalusi@linux.intel.com>]

Two issues with the way sof_set_up_widgets_in_path() adds a pipeline to
the list of pipelines to be triggered:

The count is incremented before the array entry is written, so the last
entry of the list is NULL for a short window. A concurrent user of the
list, like sof_ipc4_trigger_pipelines(), can see the incremented count
with the entry still unset.

A widget which is not part of a pipeline has no spipe, but it is still
added to the list, resulting in a NULL entry within the count.

Store the entry before incrementing the count and skip the widgets
without a pipeline.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
---
 sound/soc/sof/sof-audio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sof/sof-audio.c b/sound/soc/sof/sof-audio.c
index d244e90a734b..850eb2bc2b44 100644
--- a/sound/soc/sof/sof-audio.c
+++ b/sound/soc/sof/sof-audio.c
@@ -629,6 +629,10 @@ static int sof_set_up_widgets_in_path(struct snd_sof_dev *sdev, struct snd_soc_d
 		if (!pipeline_list->pipelines)
 			goto sink_setup;
 
+		/* a widget which is not part of a pipeline has nothing to trigger */
+		if (!swidget->spipe)
+			goto sink_setup;
+
 		/*
 		 * Add the widget's pipe_widget to the list of pipelines to be triggered if not
 		 * already in the list. This will result in the pipelines getting added in the
@@ -641,8 +645,8 @@ static int sof_set_up_widgets_in_path(struct snd_sof_dev *sdev, struct snd_soc_d
 		}
 
 		if (i == pipeline_list->count) {
-			pipeline_list->count++;
 			pipeline_list->pipelines[i] = swidget->spipe;
+			pipeline_list->count++;
 		}
 	}
 
-- 
2.55.0