Hi Iwai-san, Mark Current many drivers are using below code to know its direction. if (direction == SNDRV_PCM_STREAM_PLAYBACK) I think it should be handled by function. But is it acceptable idea ? Because it will be too many patch-set, I want to know it was acceptable idea or not before posting patch-bomb. I will post main patch, and sample driver patches. Thank you for your help !! Best regards --- Kuninori Morimoto