ASoC: codec2codec: remove ephemeral variables

Now that codec to codec links struct snd_soc_pcm_runtime have lasting pcm
and substreams, let's use them. Alsa allocate and keep the
struct snd_pcm_runtime as long as the link is powered.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20190725165949.29699-6-jbrunet@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-dapm.c

@@ -3775,6 +3775,7 @@ snd_soc_dai_link_event_pre_pmu(struct snd_soc_dapm_widget *w,
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_hw_params *params = NULL;
 	const struct snd_soc_pcm_stream *config = NULL;
+	struct snd_pcm_runtime *runtime = NULL;
 	unsigned int fmt;
 	int ret = 0;
 
@@ -3782,6 +3783,14 @@ snd_soc_dai_link_event_pre_pmu(struct snd_soc_dapm_widget *w,
 	if (!params)
 		return -ENOMEM;
 
+	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
+	if (!runtime) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	substream->runtime = runtime;
+
 	substream->stream = SNDRV_PCM_STREAM_CAPTURE;
 	snd_soc_dapm_widget_for_each_source_path(w, path) {
 		source = path->source->priv;
@@ -3808,6 +3817,8 @@ snd_soc_dai_link_event_pre_pmu(struct snd_soc_dapm_widget *w,
 		sink->active++;
 	}
 
+	substream->hw_opened = 1;
+
 	/*
 	 * Note: getting the config after .startup() gives a chance to
 	 * either party on the link to alter the configuration if
@@ -3864,6 +3875,9 @@ snd_soc_dai_link_event_pre_pmu(struct snd_soc_dapm_widget *w,
 	}
 
 out:
+	if (ret < 0)
+		kfree(runtime);
+
 	kfree(params);
 	return ret;
 }
@@ -3873,29 +3887,16 @@ static int snd_soc_dai_link_event(struct snd_soc_dapm_widget *w,
 {
 	struct snd_soc_dapm_path *path;
 	struct snd_soc_dai *source, *sink;
-	struct snd_soc_pcm_runtime *rtd = w->priv;
-	struct snd_pcm_substream substream;
-	struct snd_pcm_runtime *runtime = NULL;
-	int ret = 0;
+	struct snd_pcm_substream *substream = w->priv;
+	int ret = 0, saved_stream = substream->stream;
 
 	if (WARN_ON(list_empty(&w->edges[SND_SOC_DAPM_DIR_OUT]) ||
 		    list_empty(&w->edges[SND_SOC_DAPM_DIR_IN])))
 		return -EINVAL;
 
-	memset(&substream, 0, sizeof(substream));
-
-	/* Allocate a dummy snd_pcm_runtime for startup() and other ops() */
-	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
-	if (!runtime) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	substream.runtime = runtime;
-	substream.private_data = rtd;
-
 	switch (event) {
 	case SND_SOC_DAPM_PRE_PMU:
-		ret = snd_soc_dai_link_event_pre_pmu(w, &substream);
+		ret = snd_soc_dai_link_event_pre_pmu(w, substream);
 		if (ret < 0)
 			goto out;
 
@@ -3926,40 +3927,45 @@ static int snd_soc_dai_link_event(struct snd_soc_dapm_widget *w,
 			ret = 0;
 		}
 
-		substream.stream = SNDRV_PCM_STREAM_CAPTURE;
+		substream->stream = SNDRV_PCM_STREAM_CAPTURE;
 		snd_soc_dapm_widget_for_each_source_path(w, path) {
 			source = path->source->priv;
-			snd_soc_dai_hw_free(source, &substream);
+			snd_soc_dai_hw_free(source, substream);
 		}
 
-		substream.stream = SNDRV_PCM_STREAM_PLAYBACK;
+		substream->stream = SNDRV_PCM_STREAM_PLAYBACK;
 		snd_soc_dapm_widget_for_each_sink_path(w, path) {
 			sink = path->sink->priv;
-			snd_soc_dai_hw_free(sink, &substream);
+			snd_soc_dai_hw_free(sink, substream);
 		}
 
-		substream.stream = SNDRV_PCM_STREAM_CAPTURE;
+		substream->stream = SNDRV_PCM_STREAM_CAPTURE;
 		snd_soc_dapm_widget_for_each_source_path(w, path) {
 			source = path->source->priv;
 			source->active--;
-			snd_soc_dai_shutdown(source, &substream);
+			snd_soc_dai_shutdown(source, substream);
 		}
 
-		substream.stream = SNDRV_PCM_STREAM_PLAYBACK;
+		substream->stream = SNDRV_PCM_STREAM_PLAYBACK;
 		snd_soc_dapm_widget_for_each_sink_path(w, path) {
 			sink = path->sink->priv;
 			sink->active--;
-			snd_soc_dai_shutdown(sink, &substream);
+			snd_soc_dai_shutdown(sink, substream);
 		}
 		break;
 
+	case SND_SOC_DAPM_POST_PMD:
+		kfree(substream->runtime);
+		break;
+
 	default:
 		WARN(1, "Unknown event %d\n", event);
 		ret = -EINVAL;
 	}
 
 out:
-	kfree(runtime);
+	/* Restore the substream direction */
+	substream->stream = saved_stream;
 	return ret;
 }
 
@@ -4082,9 +4088,11 @@ snd_soc_dapm_alloc_kcontrol(struct snd_soc_card *card,
 }
 
 static struct snd_soc_dapm_widget *
-snd_soc_dapm_new_dai(struct snd_soc_card *card, struct snd_soc_pcm_runtime *rtd,
+snd_soc_dapm_new_dai(struct snd_soc_card *card,
+		     struct snd_pcm_substream *substream,
 		     char *id)
 {
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dapm_widget template;
 	struct snd_soc_dapm_widget *w;
 	const char **w_param_text;
@@ -4103,7 +4111,7 @@ snd_soc_dapm_new_dai(struct snd_soc_card *card, struct snd_soc_pcm_runtime *rtd,
 	template.name = link_name;
 	template.event = snd_soc_dai_link_event;
 	template.event_flags = SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMU |
-		SND_SOC_DAPM_PRE_PMD;
+		SND_SOC_DAPM_PRE_PMD | SND_SOC_DAPM_POST_PMD;
 	template.kcontrol_news = NULL;
 
 	/* allocate memory for control, only in case of multiple configs */
@@ -4138,7 +4146,7 @@ snd_soc_dapm_new_dai(struct snd_soc_card *card, struct snd_soc_pcm_runtime *rtd,
 		goto outfree_kcontrol_news;
 	}
 
-	w->priv = rtd;
+	w->priv = substream;
 
 	return w;
 
@@ -4260,6 +4268,8 @@ static void dapm_connect_dai_link_widgets(struct snd_soc_card *card,
 	struct snd_soc_dai *codec_dai;
 	struct snd_soc_dapm_widget *playback = NULL, *capture = NULL;
 	struct snd_soc_dapm_widget *codec, *playback_cpu, *capture_cpu;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_str *streams = rtd->pcm->streams;
 	int i;
 
 	if (rtd->dai_link->params) {
@@ -4278,7 +4288,8 @@ static void dapm_connect_dai_link_widgets(struct snd_soc_card *card,
 
 		if (playback_cpu && codec) {
 			if (!playback) {
-				playback = snd_soc_dapm_new_dai(card, rtd,
+				substream = streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
+				playback = snd_soc_dapm_new_dai(card, substream,
 								"playback");
 				if (IS_ERR(playback)) {
 					dev_err(rtd->dev,
@@ -4307,7 +4318,8 @@ static void dapm_connect_dai_link_widgets(struct snd_soc_card *card,
 
 		if (codec && capture_cpu) {
 			if (!capture) {
-				capture = snd_soc_dapm_new_dai(card, rtd,
+				substream = streams[SNDRV_PCM_STREAM_CAPTURE].substream;
+				capture = snd_soc_dapm_new_dai(card, substream,
 							       "capture");
 				if (IS_ERR(capture)) {
 					dev_err(rtd->dev,