ASoC: SOF: sof-audio: Fixes for widget prepare and

Merge series from Peter Ujfalusi <peter.ujfalusi@linux.intel.com>:

This series contains one fix (first patch) followed by a nice to have safety
belts in case we get a widget from topology which is not handled by SOF and will
not have corresponding swidget associated with.

sound/soc/sof/sof-audio.c

@@ -271,9 +271,9 @@ sof_unprepare_widgets_in_path(struct snd_sof_dev *sdev, struct snd_soc_dapm_widg
 	struct snd_sof_widget *swidget = widget->dobj.private;
 	struct snd_soc_dapm_path *p;
 
-	/* return if the widget is in use or if it is already unprepared */
-	if (!swidget->prepared || swidget->use_count > 1)
-		return;
+	/* skip if the widget is in use or if it is already unprepared */
+	if (!swidget || !swidget->prepared || swidget->use_count > 0)
+		goto sink_unprepare;
 
 	if (widget_ops[widget->id].ipc_unprepare)
 		/* unprepare the source widget */
@@ -281,6 +281,7 @@ sof_unprepare_widgets_in_path(struct snd_sof_dev *sdev, struct snd_soc_dapm_widg
 
 	swidget->prepared = false;
 
+sink_unprepare:
 	/* unprepare all widgets in the sink paths */
 	snd_soc_dapm_widget_for_each_sink_path(widget, p) {
 		if (!p->walking && p->sink->dobj.private) {
@@ -303,7 +304,7 @@ sof_prepare_widgets_in_path(struct snd_sof_dev *sdev, struct snd_soc_dapm_widget
 	struct snd_soc_dapm_path *p;
 	int ret;
 
-	if (!widget_ops[widget->id].ipc_prepare || swidget->prepared)
+	if (!swidget || !widget_ops[widget->id].ipc_prepare || swidget->prepared)
 		goto sink_prepare;
 
 	/* prepare the source widget */