Part of PCM constraints are set based on DSP topology, but rest should be set based on hardware capabilities. Add PCM constraints for Intel platforms: - Add constraint for the period count to be integer. This avoids wrap-arounds of the DMA circular buffer in middle of a period. - Align period size to dword/32bit as per HDA spec. Both constraints are aligned with current implementation in snd-hda-intel driver. Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx> --- sound/soc/sof/intel/hda-pcm.c | 7 +++++++ sound/soc/sof/intel/intel-ipc.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index b527d5958ae5..5d35bb18660a 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -225,6 +225,13 @@ int hda_dsp_pcm_open(struct snd_sof_dev *sdev, return -ENODEV; } + /* minimum as per HDA spec */ + snd_pcm_hw_constraint_step(substream->runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 4); + + /* avoid circular buffer wrap in middle of period */ + snd_pcm_hw_constraint_integer(substream->runtime, + SNDRV_PCM_HW_PARAM_PERIODS); + /* binding pcm substream to hda stream */ substream->runtime->private_data = &dsp_stream->hstream; return 0; diff --git a/sound/soc/sof/intel/intel-ipc.c b/sound/soc/sof/intel/intel-ipc.c index 310f9168c124..de66f8a82a07 100644 --- a/sound/soc/sof/intel/intel-ipc.c +++ b/sound/soc/sof/intel/intel-ipc.c @@ -73,6 +73,13 @@ int intel_pcm_open(struct snd_sof_dev *sdev, /* binding pcm substream to hda stream */ substream->runtime->private_data = stream; + /* align to DMA minimum transfer size */ + snd_pcm_hw_constraint_step(substream->runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 4); + + /* avoid circular buffer wrap in middle of period */ + snd_pcm_hw_constraint_integer(substream->runtime, + SNDRV_PCM_HW_PARAM_PERIODS); + return 0; } EXPORT_SYMBOL_NS(intel_pcm_open, SND_SOC_SOF_INTEL_HIFI_EP_IPC); -- 2.28.0
