+/*
+ * 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 audioformat *fp;
+ int count = 0, needs_knot = 0;
+ int err;
+
+ list_for_each_entry(fp, &subs->fmt_list, list) {
+ if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
+ return 0;
+ count += fp->nr_rates;
+ if (fp->needs_knot)
+ needs_knot = 1;
+ }
+ if (!needs_knot)
+ return 0;
+
+ subs->rate_list.count = count;
+ subs->rate_list.list = kmalloc(sizeof(int) * count, GFP_KERNEL);
+ subs->rate_list.mask = 0;
+ count = 0;
+ list_for_each_entry(fp, &subs->fmt_list, list) {
+ int i;
+ for (i = 0; i < fp->nr_rates; i++)
+ subs->rate_list.list[count++] = fp->rate_table[i];
+ }
+ err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+ &subs->rate_list);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+