At Wed, 3 Apr 2013 08:30:03 -0700, Dylan Reid wrote:
Allow a codec to specify a delay in addition to the delay before samples are passed through DMA. Some codecs have large processing delays because of built-in DSPs that require codec-side buffers of many milliseconds. Default to zero delay if the codec doesn't specify a callback to get the processing delay.
Signed-off-by: Dylan Reid dgreid@chromium.org
sound/pci/hda/hda_codec.c | 17 +++++++++++++++++ sound/pci/hda/hda_codec.h | 4 ++++ sound/pci/hda/hda_intel.c | 2 ++ 3 files changed, 23 insertions(+)
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 17286b3..1d792dd 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -3724,6 +3724,23 @@ void snd_hda_codec_set_power_to_all(struct hda_codec *codec, hda_nid_t fg, } EXPORT_SYMBOL_HDA(snd_hda_codec_set_power_to_all);
+/**
- snd_hda_codec_processing_delay - get the fixed delay through the codec
- @codec: HD-audio codec
- @stream: playback or capture
- This is needed for codecs that contain DSPs that cause long delays.
- */
+unsigned int snd_hda_codec_processing_delay(struct hda_codec *codec,
unsigned int stream)+{
- if (codec->patch_ops.get_processing_delay)
return codec->patch_ops.get_processing_delay(codec, stream);- return 0;
+} +EXPORT_SYMBOL_HDA(snd_hda_codec_processing_delay);
In the second thought, it would fit more better to pcm_ops than codec patch_ops. That is, the change would be like below.
Takashi
--- diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h index 23ca172..c93f902 100644 --- a/sound/pci/hda/hda_codec.h +++ b/sound/pci/hda/hda_codec.h @@ -757,6 +757,9 @@ struct hda_pcm_ops { struct snd_pcm_substream *substream); int (*cleanup)(struct hda_pcm_stream *info, struct hda_codec *codec, struct snd_pcm_substream *substream); + unsigned int (*get_delay)(struct hda_pcm_stream *info, + struct hda_codec *codec, + struct snd_pcm_substream *substream); };
/* PCM information for each substream */ diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 418bfc0..a88f016 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -2349,8 +2349,11 @@ static unsigned int azx_get_position(struct azx *chip, struct azx_dev *azx_dev, bool with_check) { + struct snd_pcm_substream *substream = azx_dev->substream; + struct azx_pcm *apcm = snd_pcm_substream_chip(substream); unsigned int pos; - int stream = azx_dev->substream->stream; + int stream = substream->stream; + struct hda_pcm_stream *hinfo = apcm->hinfo[stream]; int delay = 0;
switch (chip->position_fix[stream]) { @@ -2399,9 +2402,13 @@ static unsigned int azx_get_position(struct azx *chip, delay = 0; chip->driver_caps &= ~AZX_DCAPS_COUNT_LPIB_DELAY; } - azx_dev->substream->runtime->delay = - bytes_to_frames(azx_dev->substream->runtime, delay); + delay = bytes_to_frames(azx_dev->substream->runtime, delay); } + + if (hinfo->ops.get_delay) + delay += hinfo->ops.get_delay(hinfo, apcm->codec, substream); + azx_dev->substream->runtime->delay = delay; + trace_azx_get_position(chip, azx_dev, pos, delay); return pos; }