From 24f48799463435f5acc8924bed9ad07e85784a83 Mon Sep 17 00:00:00 2001 From: Keyon Jie Date: Wed, 17 Apr 2019 18:07:46 +0800 Subject: [PATCH 1/3] ASoC: SOF: PCM: add period_elapsed work to fix race condition in interrupt context 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 --- 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 be4984c4da4eb8..649968841dad9f 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 35e78ffecce2fe..675bb10c82f597 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 From 9f6f3fa7b78d030297cc22bece86db57101a1b36 Mon Sep 17 00:00:00 2001 From: Keyon Jie Date: Wed, 17 Apr 2019 19:00:51 +0800 Subject: [PATCH 2/3] ASoC: SOF: Intel: use snd_sof_pcm_period_elapsed Switch to a wrapper function which schedules the actual call of snd_pcm_period_elapsed after the current IPC is completed. Signed-off-by: Keyon Jie --- sound/soc/sof/intel/hda-stream.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/soc/sof/intel/hda-stream.c b/sound/soc/sof/intel/hda-stream.c index 6290b2df5e621d..47eff161c60e3d 100644 --- a/sound/soc/sof/intel/hda-stream.c +++ b/sound/soc/sof/intel/hda-stream.c @@ -465,8 +465,8 @@ irqreturn_t hda_dsp_stream_threaded_handler(int irq, void *context) { struct hdac_bus *bus = context; struct sof_intel_hda_dev *sof_hda = bus_to_sof_hda(bus); - struct hdac_stream *s; u32 status = snd_hdac_chip_readl(bus, INTSTS); + struct hdac_stream *s; u32 sd_status; /* check streams */ @@ -486,7 +486,7 @@ irqreturn_t hda_dsp_stream_threaded_handler(int irq, void *context) /* Inform ALSA only in case not do that with IPC */ if (sof_hda->no_ipc_position) - snd_pcm_period_elapsed(s->substream); + snd_sof_pcm_period_elapsed(s->substream); } } From 72733a137785ddbe4e36a284310da15bbcf9536d Mon Sep 17 00:00:00 2001 From: Keyon Jie Date: Thu, 18 Apr 2019 18:05:19 +0800 Subject: [PATCH 3/3] ASoC: SOF: ipc: use snd_sof_pcm_period_elapsed Switch to a wrapper function which schedules the actual call of snd_pcm_period_elapsed after the current IPC is completed. Signed-off-by: Keyon Jie --- sound/soc/sof/ipc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/soc/sof/ipc.c b/sound/soc/sof/ipc.c index bf58d58e737964..437e80a07bc2c4 100644 --- a/sound/soc/sof/ipc.c +++ b/sound/soc/sof/ipc.c @@ -445,7 +445,7 @@ static void ipc_period_elapsed(struct snd_sof_dev *sdev, u32 msg_id) /* only inform ALSA for period_wakeup mode */ if (!stream->substream->runtime->no_period_wakeup) - snd_pcm_period_elapsed(stream->substream); + snd_sof_pcm_period_elapsed(stream->substream); } /* DSP notifies host of an XRUN within FW */