ASoC: SOF: topology: cleanup dailinks on widget unload

We set the cpu_dai capture_ or playback_widget on widget_ready but
never clear them, which leads to failures when unloading/reloading a
topology in modprobe/rmmod tests

BugLink: https://github.com/thesofproject/linux/issues/3535
Fixes: 311ce4fe ("ASoC: SOF: Add support for loading topologies")
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220406191606.254576-1-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/topology.c

@@ -1070,6 +1070,46 @@ static int sof_connect_dai_widget(struct snd_soc_component *scomp,
 	return 0;
 }
 
+static void sof_disconnect_dai_widget(struct snd_soc_component *scomp,
+				      struct snd_soc_dapm_widget *w)
+{
+	struct snd_soc_card *card = scomp->card;
+	struct snd_soc_pcm_runtime *rtd;
+	struct snd_soc_dai *cpu_dai;
+	int i;
+
+	if (!w->sname)
+		return;
+
+	list_for_each_entry(rtd, &card->rtd_list, list) {
+		/* does stream match DAI link ? */
+		if (!rtd->dai_link->stream_name ||
+		    strcmp(w->sname, rtd->dai_link->stream_name))
+			continue;
+
+		switch (w->id) {
+		case snd_soc_dapm_dai_out:
+			for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
+				if (cpu_dai->capture_widget == w) {
+					cpu_dai->capture_widget = NULL;
+					break;
+				}
+			}
+			break;
+		case snd_soc_dapm_dai_in:
+			for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
+				if (cpu_dai->playback_widget == w) {
+					cpu_dai->playback_widget = NULL;
+					break;
+				}
+			}
+			break;
+		default:
+			break;
+		}
+	}
+}
+
 /* bind PCM ID to host component ID */
 static int spcm_bind(struct snd_soc_component *scomp, struct snd_sof_pcm *spcm,
 		     int dir)
@@ -1355,6 +1395,9 @@ static int sof_widget_unload(struct snd_soc_component *scomp,
 
 		if (dai)
 			list_del(&dai->list);
+
+		sof_disconnect_dai_widget(scomp, widget);
+
 		break;
 	default:
 		break;