int (*mmap)(struct snd_soc_component *component,
                    struct snd_pcm_substream *substream,
                    struct vm_area_struct *vma);
+       int (*ack)(struct snd_soc_component *component,
+                  struct snd_pcm_substream *substream);
 
        const struct snd_compress_ops *compress_ops;
 
                                         void *stream);
 void snd_soc_pcm_component_pm_runtime_put(struct snd_soc_pcm_runtime *rtd,
                                          void *stream, int rollback);
+int snd_soc_pcm_component_ack(struct snd_pcm_substream *substream);
 
 #endif /* __SOC_COMPONENT_H */
 
                soc_component_mark_pop(component, stream, pm);
        }
 }
+
+int snd_soc_pcm_component_ack(struct snd_pcm_substream *substream)
+{
+       struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+       struct snd_soc_component *component;
+       int i;
+
+       /* FIXME: use 1st pointer */
+       for_each_rtd_components(rtd, i, component)
+               if (component->driver->ack)
+                       return component->driver->ack(component, substream);
+
+       return 0;
+}
 
                        rtd->ops.page           = snd_soc_pcm_component_page;
                if (drv->mmap)
                        rtd->ops.mmap           = snd_soc_pcm_component_mmap;
+               if (drv->ack)
+                       rtd->ops.ack            = snd_soc_pcm_component_ack;
        }
 
        if (playback)