ASoC: SOF: ipc4: Fix pipeline state transitions for aggregate DAIs

For aggregate DAIs (num_cpus > 1) the pre_trigger/post_trigger callbacks
send pipeline state IPCs per-DAI without considering that multiple DAIs
may share the same pipeline. This causes premature state transitions
where the pipeline goes RUNNING before all link DMAs have started, or
individual DAIs send redundant IPCs for shared pipelines.

Add a per-pipeline trigger_count to gate state transitions:
- START/PAUSE_RELEASE: defer RUNNING IPC until all DAIs sharing the
  same pipeline have completed their link DMA operations
- STOP/SUSPEND/PAUSE_PUSH: use pipeline state dedup so the PAUSED IPC
  is sent once regardless of how many DAIs share the pipeline

The per-spipe DAI count is computed dynamically to handle all aggregate
topologies: shared pipelines, independent pipelines, and mixed cases.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

Author: ujfalusi

sound/soc/sof/intel/hda-dai-ops.c

@@ -292,6 +292,38 @@ static struct hdac_ext_link *sdw_get_hlink(struct snd_sof_dev *sdev,
 	return hdac_bus_eml_sdw_get_hlink(bus);
 }
 
+/*
+ * Count how many CPU DAIs in this BE link share the same pipeline (spipe)
+ * as the target. Used to determine the per-pipeline trigger threshold for
+ * aggregate DAIs where some may share a pipeline and others may not.
+ */
+static int hda_ipc4_count_spipe_dais(struct snd_pcm_substream *substream,
+				     struct snd_sof_pipeline *target_spipe)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_soc_dai *dai;
+	int count = 0;
+	int i;
+
+	for_each_rtd_cpu_dais(rtd, i, dai) {
+		struct snd_soc_dapm_widget *w;
+		struct snd_sof_widget *sw;
+
+		w = snd_soc_dai_get_widget(dai, substream->stream);
+		if (!w)
+			continue;
+
+		sw = w->dobj.private;
+		if (!sw)
+			continue;
+
+		if (sw->spipe == target_spipe)
+			count++;
+	}
+
+	return count;
+}
+
 static int hda_ipc4_pre_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *cpu_dai,
 				struct snd_pcm_substream *substream, int cmd)
 {
@@ -319,13 +351,22 @@ static int hda_ipc4_pre_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *cp
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_STOP:
+		/*
+		 * For aggregate DAIs with shared pipelines, the state check
+		 * deduplicates: the first DAI sends the IPC, subsequent DAIs
+		 * sharing the same pipeline see it already paused and skip.
+		 * For aggregate DAIs with different pipelines, each DAI pauses
+		 * its own pipeline independently.
+		 */
+		if (pipeline->state == SOF_IPC4_PIPE_PAUSED)
+			break;
+
 		ret = sof_ipc4_set_pipeline_state(sdev, pipe_widget->instance_id,
 						  SOF_IPC4_PIPE_PAUSED);
 		if (ret < 0)
 			return ret;
 
 		pipeline->state = SOF_IPC4_PIPE_PAUSED;
-
 		break;
 	default:
 		dev_err(sdev->dev, "unknown trigger command %d\n", cmd);
@@ -372,11 +413,13 @@ static int hda_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *cpu_dai,
 static int hda_ipc4_post_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *cpu_dai,
 				 struct snd_pcm_substream *substream, int cmd)
 {
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 	struct sof_ipc4_fw_data *ipc4_data = sdev->private;
 	struct snd_sof_widget *pipe_widget;
 	struct sof_ipc4_pipeline *pipeline;
 	struct snd_sof_widget *swidget;
 	struct snd_soc_dapm_widget *w;
+	int num_cpus = rtd->dai_link->num_cpus;
 	int ret = 0;
 
 	w = snd_soc_dai_get_widget(cpu_dai, substream->stream);
@@ -391,6 +434,25 @@ static int hda_ipc4_post_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *c
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
+		/*
+		 * For aggregated DAIs (num_cpus > 1), defer pipeline RUNNING
+		 * IPC until all CPU DAIs sharing this pipeline have started
+		 * their link DMAs. The per-spipe threshold handles all cases:
+		 * - shared pipeline: waits for all DAIs on the same spipe
+		 * - different pipelines: each fires independently (threshold=1)
+		 * - mixed: each group fires when its members complete
+		 */
+		if (num_cpus > 1) {
+			int spipe_dais = hda_ipc4_count_spipe_dais(substream,
+								   swidget->spipe);
+
+			swidget->spipe->trigger_count++;
+			if (swidget->spipe->trigger_count < spipe_dais)
+				break;
+
+			swidget->spipe->trigger_count = 0;
+		}
+
 		if (pipeline->state != SOF_IPC4_PIPE_PAUSED) {
 			ret = sof_ipc4_set_pipeline_state(sdev, pipe_widget->instance_id,
 							  SOF_IPC4_PIPE_PAUSED);
@@ -409,6 +471,17 @@ static int hda_ipc4_post_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *c
 		swidget->spipe->started_count++;
 		break;
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		if (num_cpus > 1) {
+			int spipe_dais = hda_ipc4_count_spipe_dais(substream,
+								   swidget->spipe);
+
+			swidget->spipe->trigger_count++;
+			if (swidget->spipe->trigger_count < spipe_dais)
+				break;
+
+			swidget->spipe->trigger_count = 0;
+		}
+
 		ret = sof_ipc4_set_pipeline_state(sdev, pipe_widget->instance_id,
 						  SOF_IPC4_PIPE_RUNNING);
 		if (ret < 0)
@@ -420,9 +493,11 @@ static int hda_ipc4_post_trigger(struct snd_sof_dev *sdev, struct snd_soc_dai *c
 	case SNDRV_PCM_TRIGGER_STOP:
 		/*
 		 * STOP/SUSPEND trigger is invoked only once when all users of this pipeline have
-		 * been stopped. So, clear the started_count so that the pipeline can be reset
+		 * been stopped. So, clear the started_count so that the pipeline can be reset.
+		 * Also reset trigger_count for aggregate DAIs in case of partial trigger rollback.
 		 */
 		swidget->spipe->started_count = 0;
+		swidget->spipe->trigger_count = 0;
 		break;
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		break;

sound/soc/sof/sof-audio.h

@@ -512,6 +512,7 @@ struct snd_sof_widget {
  * @complete: flag used to indicate that pipeline set up is complete.
  * @core_mask: Mask containing target cores for all modules in the pipeline
  * @list: List item in sdev pipeline_list
+ * @trigger_count: tracks the number of DAIs that have completed link DMA trigger for aggregate
  * @direction_valid: flag indicating if the direction is set in topology
  * @direction: pipeline direction set in topology, valid is direction_valid is true
  *
@@ -523,6 +524,7 @@ struct snd_sof_pipeline {
 	int complete;
 	unsigned long core_mask;
 	struct list_head list;
+	int trigger_count;
 	bool direction_valid;
 	u32 direction;
 };