ASoC: codec2codec: deal with params when necessary

When there is an event on codec to codec dai_link, we only need to deal
with params if the event is SND_SOC_DAPM_PRE_PMU, when .hw_params() is
called. For the other events, it is useless.

Also, dealing with the codec to codec params just before calling
.hw_params() callbacks give change to either party on the link to alter
params content in .startup(), which might be useful in some cases

Signed-off-by: Jerome Brunet <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/soc-dapm.c

···
 }
 EXPORT_SYMBOL_GPL(snd_soc_dapm_new_controls);
 
-static int snd_soc_dai_link_event(struct snd_soc_dapm_widget *w,
-				  struct snd_kcontrol *kcontrol, int event)
+static int
+snd_soc_dai_link_event_pre_pmu(struct snd_soc_dapm_widget *w,
+			       struct snd_pcm_substream *substream)
 {
 	struct snd_soc_dapm_path *path;
 	struct snd_soc_dai *source, *sink;
-	struct snd_soc_pcm_runtime *rtd = w->priv;
-	const struct snd_soc_pcm_stream *config;
-	struct snd_pcm_substream substream;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_hw_params *params = NULL;
-	struct snd_pcm_runtime *runtime = NULL;
+	const struct snd_soc_pcm_stream *config = NULL;
 	unsigned int fmt;
-	int ret = 0;
+	int ret;
 
+	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+
+	substream->stream = SNDRV_PCM_STREAM_CAPTURE;
+	snd_soc_dapm_widget_for_each_source_path(w, path) {
+		source = path->source->priv;
+
+		ret = snd_soc_dai_startup(source, substream);
+		if (ret < 0) {
+			dev_err(source->dev,
+				"ASoC: startup() failed: %d\n", ret);
+			goto out;
+		}
+		source->active++;
+	}
+
+	substream->stream = SNDRV_PCM_STREAM_PLAYBACK;
+	snd_soc_dapm_widget_for_each_sink_path(w, path) {
+		sink = path->sink->priv;
+
+		ret = snd_soc_dai_startup(sink, substream);
+		if (ret < 0) {
+			dev_err(sink->dev,
+				"ASoC: startup() failed: %d\n", ret);
+			goto out;
+		}
+		sink->active++;
+	}
+
+	/*
+	 * Note: getting the config after .startup() gives a chance to
+	 * either party on the link to alter the configuration if
+	 * necessary
+	 */
 	config = rtd->dai_link->params + rtd->params_select;
-
-	if (WARN_ON(!config) ||
-	    WARN_ON(list_empty(&w->edges[SND_SOC_DAPM_DIR_OUT]) ||
-		    list_empty(&w->edges[SND_SOC_DAPM_DIR_IN])))
-		return -EINVAL;
+	if (WARN_ON(!config)) {
+		dev_err(w->dapm->dev, "ASoC: link config missing\n");
+		ret = -EINVAL;
+		goto out;
+	}
 
 	/* Be a little careful as we don't want to overflow the mask array */
 	if (config->formats) {
···
 	} else {
 		dev_warn(w->dapm->dev, "ASoC: Invalid format %llx specified\n",
 			 config->formats);
-		fmt = 0;
-	}
 
-	/* Currently very limited parameter selection */
-	params = kzalloc(sizeof(*params), GFP_KERNEL);
-	if (!params) {
-		ret = -ENOMEM;
+		ret = -EINVAL;
 		goto out;
 	}
-	snd_mask_set(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT), fmt);
 
+	snd_mask_set(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT), fmt);
 	hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE)->min =
 		config->rate_min;
 	hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE)->max =
 		config->rate_max;
-
 	hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS)->min
 		= config->channels_min;
 	hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS)->max
 		= config->channels_max;
+
+	substream->stream = SNDRV_PCM_STREAM_CAPTURE;
+	snd_soc_dapm_widget_for_each_source_path(w, path) {
+		source = path->source->priv;
+
+		ret = snd_soc_dai_hw_params(source, substream, params);
+		if (ret < 0)
+			goto out;
+
+		dapm_update_dai_unlocked(substream, params, source);
+	}
+
+	substream->stream = SNDRV_PCM_STREAM_PLAYBACK;
+	snd_soc_dapm_widget_for_each_sink_path(w, path) {
+		sink = path->sink->priv;
+
+		ret = snd_soc_dai_hw_params(sink, substream, params);
+		if (ret < 0)
+			goto out;
+
+		dapm_update_dai_unlocked(substream, params, sink);
+	}
+
+out:
+	kfree(params);
+	return 0;
+}
+
+static int snd_soc_dai_link_event(struct snd_soc_dapm_widget *w,
+				  struct snd_kcontrol *kcontrol, int event)
+{
+	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;
+
+	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));
 
···
 
 	switch (event) {
 	case SND_SOC_DAPM_PRE_PMU:
-		substream.stream = SNDRV_PCM_STREAM_CAPTURE;
-		snd_soc_dapm_widget_for_each_source_path(w, path) {
-			source = path->source->priv;
+		ret = snd_soc_dai_link_event_pre_pmu(w, &substream);
+		if (ret < 0)
+			goto out;
 
-			ret = snd_soc_dai_startup(source, &substream);
-			if (ret < 0) {
-				dev_err(source->dev,
-					"ASoC: startup() failed: %d\n", ret);
-				goto out;
-			}
-			source->active++;
-		}
-
-		substream.stream = SNDRV_PCM_STREAM_PLAYBACK;
-		snd_soc_dapm_widget_for_each_sink_path(w, path) {
-			sink = path->sink->priv;
-
-			ret = snd_soc_dai_startup(sink, &substream);
-			if (ret < 0) {
-				dev_err(sink->dev,
-					"ASoC: startup() failed: %d\n", ret);
-				goto out;
-			}
-			sink->active++;
-		}
-
-		substream.stream = SNDRV_PCM_STREAM_CAPTURE;
-		snd_soc_dapm_widget_for_each_source_path(w, path) {
-			source = path->source->priv;
-
-			ret = snd_soc_dai_hw_params(source, &substream, params);
-			if (ret < 0)
-				goto out;
-
-			dapm_update_dai_unlocked(&substream, params, source);
-		}
-
-		substream.stream = SNDRV_PCM_STREAM_PLAYBACK;
-		snd_soc_dapm_widget_for_each_sink_path(w, path) {
-			sink = path->sink->priv;
-
-			ret = snd_soc_dai_hw_params(sink, &substream, params);
-			if (ret < 0)
-				goto out;
-
-			dapm_update_dai_unlocked(&substream, params, sink);
-		}
 		break;
 
 	case SND_SOC_DAPM_POST_PMU:
···
 
 out:
 	kfree(runtime);
-	kfree(params);
 	return ret;
 }