1 files changed, 23 insertions, 6 deletions

diff --git a/sound/firewire/fireface/ff-pcm.c b/sound/firewire/fireface/ff-pcm.c
index 4f2208202494..415bc9ccd1c7 100644
--- a/sound/firewire/fireface/ff-pcm.c
+++ b/sound/firewire/fireface/ff-pcm.c
@@ -139,6 +139,7 @@ static int pcm_init_hw_params(struct snd_ff *ff,
 static int pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_ff *ff = substream->private_data;
+	struct amdtp_domain *d = &ff->domain;
 	unsigned int rate;
 	enum snd_ff_clock_src src;
 	int i, err;
@@ -155,16 +156,21 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	if (err < 0)
 		goto release_lock;
 
+	mutex_lock(&ff->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_FF_CLOCK_SRC_INTERNAL) {
 		for (i = 0; i < CIP_SFC_COUNT; ++i) {
 			if (amdtp_rate_table[i] == rate)
 				break;
 		}
-		/*
-		 * The unit is configured at sampling frequency which packet
-		 * streaming engine can't support.
-		 */
+
+		// The unit is configured at sampling frequency which packet
+		// streaming engine can't support.
 		if (i >= CIP_SFC_COUNT) {
+			mutex_unlock(&ff->mutex);
 			err = -EIO;
 			goto release_lock;
 		}
@@ -172,14 +178,25 @@ static int pcm_open(struct snd_pcm_substream *substream)
 		substream->runtime->hw.rate_min = rate;
 		substream->runtime->hw.rate_max = rate;
 	} else {
-		if (amdtp_stream_pcm_running(&ff->rx_stream) ||
-		    amdtp_stream_pcm_running(&ff->tx_stream)) {
+		if (ff->substreams_counter > 0) {
+			unsigned int frames_per_period = d->events_per_period;
+
 			rate = amdtp_rate_table[ff->rx_stream.sfc];
 			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(&ff->mutex);
+				goto release_lock;
+			}
 		}
 	}
 
+	mutex_unlock(&ff->mutex);
+
 	snd_pcm_set_sync(substream);
 
 	return 0;