}
 }
 
-static int soc_rtdcom_ack(struct snd_pcm_substream *substream)
-{
-       struct snd_soc_pcm_runtime *rtd = substream->private_data;
-       struct snd_soc_rtdcom_list *rtdcom;
-       struct snd_soc_component *component;
-
-       for_each_rtdcom(rtd, rtdcom) {
-               component = rtdcom->component;
-
-               if (!component->driver->ops ||
-                   !component->driver->ops->ack)
-                       continue;
-
-               /* FIXME. it returns 1st ask now */
-               return component->driver->ops->ack(substream);
-       }
-
-       return -EINVAL;
-}
-
 static int soc_rtdcom_copy_user(struct snd_pcm_substream *substream, int channel,
                                unsigned long pos, void __user *buf,
                                unsigned long bytes)
                if (!ops)
                        continue;
 
-               if (ops->ack)
-                       rtd->ops.ack            = soc_rtdcom_ack;
                if (ops->copy_user)
                        rtd->ops.copy_user      = soc_rtdcom_copy_user;
                if (ops->copy_kernel)