ACK callback is useful to notify application pointer in DMA buffer to DSP, because it is called after application pointer is updated in ALSA. DSP can use the pointer to control preprocessing, detect underrun and so on. I'd like to revive it from 5.4 if it is possible. This patch is created in for-linus branch. Gyeongtaek Lee (1): ASoC: soc-component: add snd_soc_component_ack() include/sound/soc-component.h | 3 +++ sound/soc/soc-component.c | 14 ++++++++++++++ sound/soc/soc-pcm.c | 2 ++ 3 files changed, 19 insertions(+) base-commit: 52ac54e1de31af2d40f10dd4e711e774655e091b -- 2.21.0
