1 files changed, 27 insertions, 12 deletions

diff --git a/sound/firewire/bebob/bebob_pcm.c b/sound/firewire/bebob/bebob_pcm.c
index 3b2227abf8a9..516c9874f4a1 100644
--- a/sound/firewire/bebob/bebob_pcm.c
+++ b/sound/firewire/bebob/bebob_pcm.c
@@ -129,18 +129,17 @@ end:
 	return err;
 }
 
-static int
-pcm_open(struct snd_pcm_substream *substream)
+static int pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	const struct snd_bebob_rate_spec *spec = bebob->spec->rate;
-	unsigned int sampling_rate;
+	struct amdtp_domain *d = &bebob->domain;
 	enum snd_bebob_clock_type src;
 	int err;
 
 	err = snd_bebob_stream_lock_try(bebob);
 	if (err < 0)
-		goto end;
+		return err;
 
 	err = pcm_init_hw_params(bebob, substream);
 	if (err < 0)
@@ -150,15 +149,19 @@ pcm_open(struct snd_pcm_substream *substream)
 	if (err < 0)
 		goto err_locked;
 
-	/*
-	 * When source of clock is internal or any PCM stream are running,
-	 * the available sampling rate is limited at current sampling rate.
-	 */
+	mutex_lock(&bebob->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 (src == SND_BEBOB_CLOCK_TYPE_EXTERNAL ||
-	    amdtp_stream_pcm_running(&bebob->tx_stream) ||
-	    amdtp_stream_pcm_running(&bebob->rx_stream)) {
+	    (bebob->substreams_counter > 0 && d->events_per_period > 0)) {
+		unsigned int frames_per_period = d->events_per_period;
+		unsigned int sampling_rate;
+
 		err = spec->get(bebob, &sampling_rate);
 		if (err < 0) {
+			mutex_unlock(&bebob->mutex);
 			dev_err(&bebob->unit->device,
 				"fail to get sampling rate: %d\n", err);
 			goto err_locked;
@@ -166,11 +169,23 @@ pcm_open(struct snd_pcm_substream *substream)
 
 		substream->runtime->hw.rate_min = sampling_rate;
 		substream->runtime->hw.rate_max = sampling_rate;
+
+		if (frames_per_period > 0) {
+			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(&bebob->mutex);
+				goto err_locked;
+			}
+		}
 	}
 
+	mutex_unlock(&bebob->mutex);
+
 	snd_pcm_set_sync(substream);
-end:
-	return err;
+
+	return 0;
 err_locked:
 	snd_bebob_stream_lock_release(bebob);
 	return err;