return 0;
 }
 
-static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
-{
-       unsigned int aref;
-
-       /*  disable reporting invalid arefs... maybe someday */
-       return 0;
-
-       aref = CR_AREF(chanspec);
-       switch (aref) {
-       case AREF_DIFF:
-               if (s->subdev_flags & SDF_DIFF)
-                       return 0;
-               break;
-       case AREF_COMMON:
-               if (s->subdev_flags & SDF_COMMON)
-                       return 0;
-               break;
-       case AREF_GROUND:
-               if (s->subdev_flags & SDF_GROUND)
-                       return 0;
-               break;
-       case AREF_OTHER:
-               if (s->subdev_flags & SDF_OTHER)
-                       return 0;
-               break;
-       default:
-               break;
-       }
-       dev_dbg(s->device->class_dev, "subdevice does not support aref %i",
-               aref);
-       return 1;
-}
-
 /**
  * comedi_check_chanlist() - Validate each element in a chanlist.
  * @s: comedi_subdevice struct
                else
                        range_len = 0;
                if (chan >= s->n_chan ||
-                   CR_RANGE(chanspec) >= range_len ||
-                   aref_invalid(s, chanspec)) {
+                   CR_RANGE(chanspec) >= range_len) {
                        dev_warn(dev->class_dev,
                                 "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
                                 i, chanspec, chan, range_len);