ASoC: SOF: pcm: Add an option to skip platform trigger during stop

In the case of IPC4, a pipeline is only paused during STOP/PAUSE/SUSPEND
triggers and the FW keeps the host DMA running when a pipeline is
paused. The start/stop tests iterate through STOP/START triggers without
involving a hw_free. This means that the pipeline state will only toggle
between PAUSED (during the STOP trigger) and RUNNING (during the START
trigger). So this test should be treated in the same way as a
PAUSE_PUSH/PAUSE_RELEASE test and the DMA should be kept running when
toggling the pipeline states between PAUSED and RUNNING.

Since there is no way to tell if a STOP trigger will be followed by hw_free
or not, this patch proposes to always skip DMA stop during the STOP trigger
and handle it later during hw_free. Introduce a new flag in struct
sof_ipc_pcm_ops, delayed_platform_trigger, that will be used to ensure that
the host DMA will not be stopped during the STOP/PAUSE/RELEASE triggers
and set it for IPC4. The platform_trigger call to stop the DMA will be
invoked during PCM hw_free instead when the pipeline is reset.

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>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230420114137.27613-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-audio.h b/sound/soc/sof/sof-audio.h
index 6c64376858b3..a090a9eb4828 100644
--- a/sound/soc/sof/sof-audio.h
+++ b/sound/soc/sof/sof-audio.h
@@ -108,6 +108,11 @@ struct snd_sof_dai_config_data {
  *				 STOP pcm trigger
  * @ipc_first_on_start: Send IPC before invoking platform trigger during
  *				START/PAUSE_RELEASE triggers
+ * @platform_stop_during_hw_free: Invoke the platform trigger during hw_free. This is needed for
+ *				  IPC4 where a pipeline is only paused during stop/pause/suspend
+ *				  triggers. The FW keeps the host DMA running in this case and
+ *				  therefore the host must do the same and should stop the DMA during
+ *				  hw_free.
  */
 struct sof_ipc_pcm_ops {
 	int (*hw_params)(struct snd_soc_component *component, struct snd_pcm_substream *substream,
@@ -123,6 +128,7 @@ struct sof_ipc_pcm_ops {
 				   struct snd_pcm_substream *substream);
 	bool reset_hw_params_during_stop;
 	bool ipc_first_on_start;
+	bool platform_stop_during_hw_free;
 };
 
 /**