static int pcm_open(struct snd_pcm_substream *substream)
{
struct snd_tscm *tscm = substream->private_data;
+ struct amdtp_domain *d = &tscm->domain;
enum snd_tscm_clock clock;
- unsigned int rate;
int err;
err = snd_tscm_stream_lock_try(tscm);
if (err < 0)
- goto end;
+ return err;
err = pcm_init_hw_params(tscm, substream);
if (err < 0)
if (err < 0)
goto err_locked;
- if (clock != SND_TSCM_CLOCK_INTERNAL ||
- amdtp_stream_pcm_running(&tscm->rx_stream) ||
- amdtp_stream_pcm_running(&tscm->tx_stream)) {
+ mutex_lock(&tscm->mutex);
+
+ // When source of clock is not internal or any stream is reserved for
+ // transmission of PCM frames, the available sampling rate is limited
+ // at current one.
+ if (clock != SND_TSCM_CLOCK_INTERNAL || tscm->substreams_counter > 0) {
+ unsigned int frames_per_period = d->events_per_period;
+ unsigned int rate;
+
err = snd_tscm_stream_get_rate(tscm, &rate);
- if (err < 0)
+ if (err < 0) {
+ mutex_unlock(&tscm->mutex);
goto err_locked;
+ }
substream->runtime->hw.rate_min = rate;
substream->runtime->hw.rate_max = rate;
+
+ err = snd_pcm_hw_constraint_minmax(substream->runtime,
+ SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+ frames_per_period, frames_per_period);
+ if (err < 0) {
+ mutex_unlock(&tscm->mutex);
+ goto err_locked;
+ }
}
+ mutex_unlock(&tscm->mutex);
+
snd_pcm_set_sync(substream);
-end:
- return err;
+
+ return 0;
err_locked:
snd_tscm_stream_lock_release(tscm);
return err;