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@xxxxxxxxxxxx>
> ---
> 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;
}
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