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ASoC: SOF: reset DMA state in prepare

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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: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-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: Mark Brown <broonie@kernel.org>
This commit is contained in:
Kai Vehmanen 2019-07-22 09:13:43 -05:00 committed by Mark Brown
parent f1b1b9b136
commit 04c8027764
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
3 changed files with 17 additions and 14 deletions
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27
sound/soc/sof/pcm.c
View File

@ -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)

2
sound/soc/sof/pm.c
View File

@ -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;
}
}

2
sound/soc/sof/sof-priv.h
View File

@ -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 */