Unverified Commit 04c80277 authored by Kai Vehmanen's avatar Kai Vehmanen Committed by Mark Brown
Browse files

ASoC: SOF: reset DMA state in prepare 



When application goes through SUSPEND/STOP->PREPARE->START
cycle, we should always reprogram the SOF device to start
DMA from a known state so that hw_ptr/appl_ptrs remain valid.
This is expected by ALSA core as it resets the buffer
state as part of prepare (see snd_pcm_do_prepare()).

Fix the issue by forcing reconfiguration of the FW with
STREAM_PCM_PARAMS in prepare(). Use combined logic to handle
prepare and the existing flow to reprogram hw-params after
system suspend.

Without the fix, first call to pcm pointer() will return
an invalid hw_ptr and application may immediately observe XRUN
status, unless "start_threshold" SW parameter is set to maximum
value by the application.

Signed-off-by: default avatarKai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190722141402.7194-3-pierre-louis.bossart@linux.intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f1b1b9b1

sound/soc/sof/pcm.c

+15 −12
Original line number Diff line number Diff line
@@ -208,12 +208,11 @@ static int sof_pcm_hw_params(struct snd_pcm_substream *substream, 
	if (ret < 0)

		return ret;



	spcm->prepared[substream->stream] = true;



	/* save pcm hw_params */

	memcpy(&spcm->params[substream->stream], params, sizeof(*params));



	/* clear hw_params_upon_resume flag */

	spcm->hw_params_upon_resume[substream->stream] = 0;



	return ret;

}
@@ -236,6 +235,9 @@ static int sof_pcm_hw_free(struct snd_pcm_substream *substream) 
	if (!spcm)

		return -EINVAL;



	if (!spcm->prepared[substream->stream])

		return 0;



	dev_dbg(sdev->dev, "pcm: free stream %d dir %d\n", spcm->pcm.pcm_id,

		substream->stream);
@@ -258,6 +260,8 @@ static int sof_pcm_hw_free(struct snd_pcm_substream *substream) 
	if (ret < 0)

		dev_err(sdev->dev, "error: platform hw free failed\n");



	spcm->prepared[substream->stream] = false;



	return ret;

}
@@ -278,11 +282,7 @@ static int sof_pcm_prepare(struct snd_pcm_substream *substream) 
	if (!spcm)

		return -EINVAL;



	/*

	 * check if hw_params needs to be set-up again.

	 * This is only needed when resuming from system sleep.

	 */

	if (!spcm->hw_params_upon_resume[substream->stream])

	if (spcm->prepared[substream->stream])

		return 0;



	dev_dbg(sdev->dev, "pcm: prepare stream %d dir %d\n", spcm->pcm.pcm_id,
@@ -311,6 +311,7 @@ static int sof_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 
	struct snd_sof_pcm *spcm;

	struct sof_ipc_stream stream;

	struct sof_ipc_reply reply;

	bool reset_hw_params = false;

	int ret;



	/* nothing to do for BE */
@@ -351,6 +352,7 @@ static int sof_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 
	case SNDRV_PCM_TRIGGER_SUSPEND:

	case SNDRV_PCM_TRIGGER_STOP:

		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_STOP;

		reset_hw_params = true;

		break;

	default:

		dev_err(sdev->dev, "error: unhandled trigger cmd %d\n", cmd);
@@ -363,17 +365,17 @@ static int sof_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 
	ret = sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,

				 sizeof(stream), &reply, sizeof(reply));



	if (ret < 0 || cmd != SNDRV_PCM_TRIGGER_SUSPEND)

	if (ret < 0 || !reset_hw_params)

		return ret;



	/*

	 * The hw_free op is usually called when the pcm stream is closed.

	 * Since the stream is not closed during suspend, the DSP needs to be

	 * notified explicitly to free pcm to prevent errors upon resume.

	 * In case of stream is stopped, DSP must be reprogrammed upon

	 * restart, so free PCM here.

	 */

	stream.hdr.size = sizeof(stream);

	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE;

	stream.comp_id = spcm->stream[substream->stream].comp_id;

	spcm->prepared[substream->stream] = false;



	/* send IPC to the DSP */

	return sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,
@@ -481,6 +483,7 @@ static int sof_pcm_open(struct snd_pcm_substream *substream) 
	spcm->stream[substream->stream].posn.host_posn = 0;

	spcm->stream[substream->stream].posn.dai_posn = 0;

	spcm->stream[substream->stream].substream = substream;

	spcm->prepared[substream->stream] = false;



	ret = snd_sof_pcm_platform_open(sdev, substream);

	if (ret < 0)

sound/soc/sof/pm.c

+1 −1
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ static int sof_set_hw_params_upon_resume(struct snd_sof_dev *sdev) 


			state = substream->runtime->status->state;

			if (state == SNDRV_PCM_STATE_SUSPENDED)

				spcm->hw_params_upon_resume[dir] = 1;

				spcm->prepared[dir] = false;

		}

	}

sound/soc/sof/sof-priv.h

+1 −1
Original line number Diff line number Diff line
@@ -297,7 +297,7 @@ struct snd_sof_pcm { 
	struct snd_sof_pcm_stream stream[2];

	struct list_head list;	/* list in sdev pcm list */

	struct snd_pcm_hw_params params[2];

	int hw_params_upon_resume[2]; /* set up hw_params upon resume */

	bool prepared[2]; /* PCM_PARAMS set successfully */

};



/* ALSA SOF Kcontrol device */

CRA Git | Maintained and supported by SUSTech CRA and CCSE