snd_usb_pcm_open 1983 sound/usb/usbaudio.c 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
snd_usb_pcm_open 1993 sound/usb/usbaudio.c 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);