From: Keyon Jie yang.jie@linux.intel.com
The IPC implementation in SOF requires sending IPCs serially: we should not send a new IPC command to the firmware before we get an ACK (or time out) from firmware, and the IRQ processing is complete.
snd_pcm_period_elapsed() can be called in interrupt context before IRQ_HANDLED is returned. When the PCM is done draining, a STOP IPC will then be sent, which breaks the expectation that IPCs are handled serially and leads to IPC timeouts.
This patch adds a workqueue to defer the call to snd_pcm_elapsed() after the IRQ is handled.
Signed-off-by: Keyon Jie yang.jie@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/soc/sof/pcm.c | 48 ++++++++++++++++++++++++++++++++++++++++ sound/soc/sof/sof-priv.h | 2 ++ 2 files changed, 50 insertions(+)
diff --git a/sound/soc/sof/pcm.c b/sound/soc/sof/pcm.c index be4984c4da4e..649968841dad 100644 --- a/sound/soc/sof/pcm.c +++ b/sound/soc/sof/pcm.c @@ -52,6 +52,48 @@ static int sof_pcm_dsp_params(struct snd_sof_pcm *spcm, struct snd_pcm_substream return ret; }
+/* + * sof pcm period elapse work + */ +static void sof_pcm_period_elapsed_work(struct work_struct *work) +{ + struct snd_sof_pcm_stream *sps = + container_of(work, struct snd_sof_pcm_stream, + period_elapsed_work); + + snd_pcm_period_elapsed(sps->substream); +} + +/* + * sof pcm period elapse, this could be called at irq thread context. + */ +void snd_sof_pcm_period_elapsed(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, DRV_NAME); + struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component); + struct snd_sof_pcm *spcm; + + spcm = snd_sof_find_spcm_dai(sdev, rtd); + if (!spcm) { + dev_err(sdev->dev, + "error: period elapsed for unknown stream!\n"); + return; + } + + /* + * snd_pcm_period_elapsed() can be called in interrupt context + * before IRQ_HANDLED is returned. Inside snd_pcm_period_elapsed(), + * when the PCM is done draining or xrun happened, a STOP IPC will + * then be sent and this IPC will hit IPC timeout. + * To avoid sending IPC before the previous IPC is handled, we + * schedule delayed work here to call the snd_pcm_period_elapsed(). + */ + schedule_work(&spcm->stream[substream->stream].period_elapsed_work); +} +EXPORT_SYMBOL(snd_sof_pcm_period_elapsed); + /* this may get called several times by oss emulation */ static int sof_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) @@ -169,6 +211,9 @@ static int sof_pcm_hw_params(struct snd_pcm_substream *substream, /* save pcm hw_params */ memcpy(&spcm->params[substream->stream], params, sizeof(*params));
+ INIT_WORK(&spcm->stream[substream->stream].period_elapsed_work, + sof_pcm_period_elapsed_work); + return ret; }
@@ -203,6 +248,9 @@ static int sof_pcm_hw_free(struct snd_pcm_substream *substream) sizeof(stream), &reply, sizeof(reply));
snd_pcm_lib_free_pages(substream); + + cancel_work_sync(&spcm->stream[substream->stream].period_elapsed_work); + return ret; }
diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h index 35e78ffecce2..675bb10c82f5 100644 --- a/sound/soc/sof/sof-priv.h +++ b/sound/soc/sof/sof-priv.h @@ -274,6 +274,7 @@ struct snd_sof_pcm_stream { struct snd_dma_buffer page_table; struct sof_ipc_stream_posn posn; struct snd_pcm_substream *substream; + struct work_struct period_elapsed_work; };
/* ALSA SOF PCM device */ @@ -495,6 +496,7 @@ struct snd_sof_pcm *snd_sof_find_spcm_comp(struct snd_sof_dev *sdev, int *direction); struct snd_sof_pcm *snd_sof_find_spcm_pcm_id(struct snd_sof_dev *sdev, unsigned int pcm_id); +void snd_sof_pcm_period_elapsed(struct snd_pcm_substream *substream);
/* * Stream IPC