ASoC: SOF: topology: read back control data from DSP

Read back the control data from the DSP to initialize the control data
size to match that of the data in the DSP. This is particularly useful
for volatile read-only kcontrols in static pipelines.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20211215180404.53254-9-ranjani.sridharan@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/sof-audio.c

@@ -59,12 +59,26 @@ static int sof_widget_kcontrol_setup(struct snd_sof_dev *sdev, struct snd_sof_wi
 	/* set up all controls for the widget */
 	list_for_each_entry(scontrol, &sdev->kcontrol_list, list)
 		if (scontrol->comp_id == swidget->comp_id) {
+			/* set kcontrol data in DSP */
 			ret = sof_kcontrol_setup(sdev, scontrol);
 			if (ret < 0) {
 				dev_err(sdev->dev, "error: fail to set up kcontrols for widget %s\n",
 					swidget->widget->name);
 				return ret;
 			}
+
+			/*
+			 * Read back the data from the DSP for static widgets. This is particularly
+			 * useful for binary kcontrols associated with static pipeline widgets to
+			 * initialize the data size to match that in the DSP.
+			 */
+			if (swidget->dynamic_pipeline_widget)
+				continue;
+
+			ret = snd_sof_ipc_set_get_comp_data(scontrol, false);
+			if (ret < 0)
+				dev_warn(sdev->dev, "Failed kcontrol get for control in widget %s\n",
+					 swidget->widget->name);
 		}
 
 	return 0;