1 files changed, 33 insertions, 3 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9557bd4d1bbc..99a66d0ef5b2 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -157,6 +157,31 @@ find_substream_format(struct snd_usb_substream *subs,
 			   true, subs);
 }
 
+bool snd_usb_pcm_has_fixed_rate(struct snd_usb_substream *subs)
+{
+	const struct audioformat *fp;
+	struct snd_usb_audio *chip = subs->stream->chip;
+	int rate = -1;
+
+	if (!(chip->quirk_flags & QUIRK_FLAG_FIXED_RATE))
+		return false;
+	list_for_each_entry(fp, &subs->fmt_list, list) {
+		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
+			return false;
+		if (fp->nr_rates < 1)
+			continue;
+		if (fp->nr_rates > 1)
+			return false;
+		if (rate < 0) {
+			rate = fp->rate_table[0];
+			continue;
+		}
+		if (rate != fp->rate_table[0])
+			return false;
+	}
+	return true;
+}
+
 static int init_pitch_v1(struct snd_usb_audio *chip, int ep)
 {
 	struct usb_device *dev = chip->dev;
@@ -450,12 +475,14 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	struct snd_usb_audio *chip = subs->stream->chip;
 	const struct audioformat *fmt;
 	const struct audioformat *sync_fmt;
+	bool fixed_rate, sync_fixed_rate;
 	int ret;
 
 	ret = snd_media_start_pipeline(subs);
 	if (ret)
 		return ret;
 
+	fixed_rate = snd_usb_pcm_has_fixed_rate(subs);
 	fmt = find_substream_format(subs, hw_params);
 	if (!fmt) {
 		usb_audio_dbg(chip,
@@ -469,7 +496,8 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	if (fmt->implicit_fb) {
 		sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
 								hw_params,
-								!substream->stream);
+								!substream->stream,
+								&sync_fixed_rate);
 		if (!sync_fmt) {
 			usb_audio_dbg(chip,
 				      "cannot find sync format: ep=0x%x, iface=%d:%d, format=%s, rate=%d, channels=%d\n",
@@ -482,6 +510,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		}
 	} else {
 		sync_fmt = fmt;
+		sync_fixed_rate = fixed_rate;
 	}
 
 	ret = snd_usb_lock_shutdown(chip);
@@ -499,7 +528,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		close_endpoints(chip, subs);
 	}
 
-	subs->data_endpoint = snd_usb_endpoint_open(chip, fmt, hw_params, false);
+	subs->data_endpoint = snd_usb_endpoint_open(chip, fmt, hw_params, false, fixed_rate);
 	if (!subs->data_endpoint) {
 		ret = -EINVAL;
 		goto unlock;
@@ -508,7 +537,8 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	if (fmt->sync_ep) {
 		subs->sync_endpoint = snd_usb_endpoint_open(chip, sync_fmt,
 							    hw_params,
-							    fmt == sync_fmt);
+							    fmt == sync_fmt,
+							    sync_fixed_rate);
 		if (!subs->sync_endpoint) {
 			ret = -EINVAL;
 			goto unlock;