Hi Sakamoto-san > It is better to rename these inline functions introduced in this > patchset so that they belong to PCM category, since in Linux sound > subsystem there is another type of substream in rawmidi category. > > The concept of 'substream' corresponds to 'subdevice' in some operations > to PCM/RawMidi cdev, thus should be handled with enough care as much as > possible, in my opinion. Ah, indeed. Thank you for pointing it. So something like snd_stream_is_playback() -> snd_pcm_stream_is_playback() snd_substream_is_playback() -> snd_pcm_substream_is_playback() Thank you for your help !! Best regards --- Kuninori Morimoto