From: Kai Vehmanen kai.vehmanen@linux.intel.com
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 --- sound/soc/sof/pcm.c | 27 +++++++++++++++------------ sound/soc/sof/pm.c | 2 +- sound/soc/sof/sof-priv.h | 2 +- 3 files changed, 17 insertions(+), 14 deletions(-)
diff --git a/sound/soc/sof/pcm.c b/sound/soc/sof/pcm.c index 334e9d59b1ba..3b8955e755b2 100644 --- a/sound/soc/sof/pcm.c +++ b/sound/soc/sof/pcm.c @@ -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) diff --git a/sound/soc/sof/pm.c b/sound/soc/sof/pm.c index 278abfd10490..48c6d78d72e2 100644 --- a/sound/soc/sof/pm.c +++ b/sound/soc/sof/pm.c @@ -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; } }
diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h index b8c0b2a22684..fa5cb7d2a660 100644 --- a/sound/soc/sof/sof-priv.h +++ b/sound/soc/sof/sof-priv.h @@ -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 */