4 Apr
2019
4 Apr
'19
1:37 p.m.
On Thu, 21 Mar 2019 17:10:07 +0100, Pierre-Louis Bossart wrote:
+/* this may get called several times by oss emulation */ +static int sof_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)+{
....
- /* container size */
- switch (params_width(params)) {
- case 16:
pcm.params.sample_container_bytes = 2;break;- case 24:
pcm.params.sample_container_bytes = 4;break;- case 32:
pcm.params.sample_container_bytes = 4;break;- default:
return -EINVAL;- }
This can be simply snd_pcm_format_physical_width() / 8.
+static int sof_pcm_open(struct snd_pcm_substream *substream) +{
....
- /* set any runtime constraints based on topology */
- snd_pcm_hw_constraint_step(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_BUFFER_SIZE,le32_to_cpu(caps->period_size_min));- snd_pcm_hw_constraint_step(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_PERIOD_SIZE,le32_to_cpu(caps->period_size_min));
Is period_size_min in frames or in bytes? The code below refers as byte size while this refers as frames, so they look inconsistent.
- /* set runtime config */
- runtime->hw.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |SNDRV_PCM_INFO_INTERLEAVED |SNDRV_PCM_INFO_PAUSE |SNDRV_PCM_INFO_RESUME |SNDRV_PCM_INFO_NO_PERIOD_WAKEUP;
Does SOF support the full resume? That is, the stream gets resumed at the exact position that was suspended. Most devices can't, hence they don't set *_INFO_RESUME flag and let user-space restarting.
- runtime->hw.period_bytes_min = le32_to_cpu(caps->period_size_min);
- runtime->hw.period_bytes_max = le32_to_cpu(caps->period_size_max);
- runtime->hw.periods_min = le32_to_cpu(caps->periods_min);
- runtime->hw.periods_max = le32_to_cpu(caps->periods_max);
- runtime->hw.buffer_bytes_max = le32_to_cpu(caps->buffer_size_max);
These refer as bytes...
thanks,
Takashi