For delay calculation we need two information: Number of bytes transferred between the DSP and host memory (ALSA buffer) Number of frames transferred between the DSP and external device (link/codec/DMIC/etc).
The reason for the different units (bytes vs frames) on host and dai side is that the format on the dai side is decided by the firmware and might not be the same as on the host side, thus the expectation is that the counter reflects the number of frames. The kernel know the host side format and in there we have access to the DMA position which is in bytes.
In a simplified way, the DSP caused delay is the difference between the two counters.
The existing get_stream_position callback is defined to retrieve the frame counter on the DAI side but it's name is too generic to be intuitive and makes it hard to define a callback for the host side.
This patch introduces a new set of callbacks to replace the get_stream_position and define the host side equivalent: get_dai_frame_counter get_host_byte_counter
Subsequent patches will remove the old callback.
Cc: stable@vger.kernel.org # 6.8 Signed-off-by: Peter Ujfalusi peter.ujfalusi@linux.intel.com Reviewed-by: Kai Vehmanen kai.vehmanen@linux.intel.com Reviewed-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/soc/sof/ops.h | 24 ++++++++++++++++++++++++ sound/soc/sof/sof-priv.h | 21 +++++++++++++++++++++ 2 files changed, 45 insertions(+)
diff --git a/sound/soc/sof/ops.h b/sound/soc/sof/ops.h index 6cf21e829e07..d83cd771015c 100644 --- a/sound/soc/sof/ops.h +++ b/sound/soc/sof/ops.h @@ -533,6 +533,30 @@ static inline u64 snd_sof_pcm_get_stream_position(struct snd_sof_dev *sdev, return 0; }
+static inline u64 +snd_sof_pcm_get_dai_frame_counter(struct snd_sof_dev *sdev, + struct snd_soc_component *component, + struct snd_pcm_substream *substream) +{ + if (sof_ops(sdev) && sof_ops(sdev)->get_dai_frame_counter) + return sof_ops(sdev)->get_dai_frame_counter(sdev, component, + substream); + + return 0; +} + +static inline u64 +snd_sof_pcm_get_host_byte_counter(struct snd_sof_dev *sdev, + struct snd_soc_component *component, + struct snd_pcm_substream *substream) +{ + if (sof_ops(sdev) && sof_ops(sdev)->get_host_byte_counter) + return sof_ops(sdev)->get_host_byte_counter(sdev, component, + substream); + + return 0; +} + /* machine driver */ static inline int snd_sof_machine_register(struct snd_sof_dev *sdev, void *pdata) diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h index d453a4ce3b21..91043f177dfa 100644 --- a/sound/soc/sof/sof-priv.h +++ b/sound/soc/sof/sof-priv.h @@ -270,6 +270,27 @@ struct snd_sof_dsp_ops { struct snd_soc_component *component, struct snd_pcm_substream *substream); /* optional */
+ /* + * optional callback to retrieve the number of frames left/arrived from/to + * the DSP on the DAI side (link/codec/DMIC/etc). + * + * The callback is used when the firmware does not provide this information + * via the shared SRAM window and it can be retrieved by host. + */ + u64 (*get_dai_frame_counter)(struct snd_sof_dev *sdev, + struct snd_soc_component *component, + struct snd_pcm_substream *substream); /* optional */ + + /* + * Optional callback to retrieve the number of bytes left/arrived from/to + * the DSP on the host side (bytes between host ALSA buffer and DSP). + * + * The callback is needed for ALSA delay reporting. + */ + u64 (*get_host_byte_counter)(struct snd_sof_dev *sdev, + struct snd_soc_component *component, + struct snd_pcm_substream *substream); /* optional */ + /* host read DSP stream data */ int (*ipc_msg_data)(struct snd_sof_dev *sdev, struct snd_sof_pcm_stream *sps,