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