diff options
Diffstat (limited to 'sound/soc/sof/intel/hda-pcm.c')
| -rw-r--r-- | sound/soc/sof/intel/hda-pcm.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index 1dd8d2092c3b..da6c1e7263cd 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -29,6 +29,8 @@ #define SDnFMT_BITS(x) ((x) << 4) #define SDnFMT_CHAN(x) ((x) << 0) +#define HDA_MAX_PERIOD_TIME_HEADROOM 10 + static bool hda_always_enable_dmi_l1; module_param_named(always_enable_dmi_l1, hda_always_enable_dmi_l1, bool, 0444); MODULE_PARM_DESC(always_enable_dmi_l1, "SOF HDA always enable DMI l1"); @@ -291,19 +293,30 @@ int hda_dsp_pcm_open(struct snd_sof_dev *sdev, * On playback start the DMA will transfer dsp_max_burst_size_in_ms * amount of data in one initial burst to fill up the host DMA buffer. * Consequent DMA burst sizes are shorter and their length can vary. - * To make sure that userspace allocate large enough ALSA buffer we need - * to place a constraint on the buffer time. + * To avoid immediate xrun by the initial burst we need to place + * constraint on the period size (via PERIOD_TIME) to cover the size of + * the host buffer. + * We need to add headroom of max 10ms as the firmware needs time to + * settle to the 1ms pacing and initially it can run faster for few + * internal periods. * * On capture the DMA will transfer 1ms chunks. - * - * Exact dsp_max_burst_size_in_ms constraint is racy, so set the - * constraint to a minimum of 2x dsp_max_burst_size_in_ms. */ - if (spcm->stream[direction].dsp_max_burst_size_in_ms) + if (spcm->stream[direction].dsp_max_burst_size_in_ms) { + unsigned int period_time = spcm->stream[direction].dsp_max_burst_size_in_ms; + + /* + * add headroom over the maximum burst size to cover the time + * needed for the DMA pace to settle. + * Limit the headroom time to HDA_MAX_PERIOD_TIME_HEADROOM + */ + period_time += min(period_time, HDA_MAX_PERIOD_TIME_HEADROOM); + snd_pcm_hw_constraint_minmax(substream->runtime, - SNDRV_PCM_HW_PARAM_BUFFER_TIME, - spcm->stream[direction].dsp_max_burst_size_in_ms * USEC_PER_MSEC * 2, + SNDRV_PCM_HW_PARAM_PERIOD_TIME, + period_time * USEC_PER_MSEC, UINT_MAX); + } /* binding pcm substream to hda stream */ substream->runtime->private_data = &dsp_stream->hstream; |