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| author | Ranjani Sridharan <ranjani.sridharan@linux.intel.com> | 2021-11-19 17:08:52 -0600 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2021-11-24 12:57:21 +0000 |
| commit | 6c26b5054ce2b822856e32f1840d13f777c6f295 (patch) | |
| tree | 3adbd20594df72058e755b7675bdd42b2e8c828c /sound/soc/sof/intel/cnl.c | |
| parent | 4a39ea3f07f14f21a6b97e78c972f71fc5761d3a (diff) | |
| download | linux-6c26b5054ce2b822856e32f1840d13f777c6f295.tar.gz | |
ASoC: SOF: Intel: add .ack support for HDaudio platforms
When we disable rewinds, then the .ack can be used to program SPIB with the application pointer, which allows the HDaudio DMA to save power by opportunistically bursting data transfers when the path to memory is enabled (and conversely to shut it down when there are no transfer requests). The SPIB register can only be programmed with incremental values with wrap-around after the DMA RUN bits are set. For simplicity, we set the INFO_NO_REWINDS flag in the .open callback when we already need to program the SNDRV_PCM_INFO_SYNC_APPLPTR flag. Rewinds are not used by many applications. One notable application using rewinds is PulseAudio. Practical experiments with Ubuntu/PulseAudio default settings did not show any audible issues, but the user may hear volume changes and notification with a delay, depending on the size of the ring buffer and latency constraints. The choice of disabling rewinds is exposed as a kernel parameter and not a Kconfig option to avoid any undesirable side-effects. Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Link: https://lore.kernel.org/r/20211119230852.206310-5-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/sof/intel/cnl.c')
| -rw-r--r-- | sound/soc/sof/intel/cnl.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/soc/sof/intel/cnl.c b/sound/soc/sof/intel/cnl.c index d455272bfc8e..04daaa6100f1 100644 --- a/sound/soc/sof/intel/cnl.c +++ b/sound/soc/sof/intel/cnl.c @@ -283,6 +283,7 @@ const struct snd_sof_dsp_ops sof_cnl_ops = { .pcm_hw_free = hda_dsp_stream_hw_free, .pcm_trigger = hda_dsp_pcm_trigger, .pcm_pointer = hda_dsp_pcm_pointer, + .pcm_ack = hda_dsp_pcm_ack, #if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_PROBES) /* probe callbacks */ |