+/*
+ * If the device supports unusual bit rates, does the request meet these?
+ */
+static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
+ struct snd_usb_substream *subs)
+{
+ struct list_head *p;
+ struct snd_pcm_hw_constraint_list constraints_rates;
+ int err;
+
+ list_for_each(p, &subs->fmt_list) {
+ struct audioformat *fp;
+ fp = list_entry(p, struct audioformat, list);
+
+ if (!fp->needs_knot)
+ continue;
+
+ constraints_rates.count = fp->nr_rates;
+ constraints_rates.list = fp->rate_table;
+ constraints_rates.mask = 0;
+
+ err = snd_pcm_hw_constraint_list(runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ &constraints_rates);
+
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+