> static struct snd_soc_dai_driver q6dsp_audio_fe_dais[] = { > + { > + .playback = { > + .stream_name = "USB Playback", > + .rates = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | > + SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 | > + SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | > + SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 | > + SNDRV_PCM_RATE_192000, > + .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | > + SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE | > + SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE | > + SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_U24_BE, > + .channels_min = 1, > + .channels_max = 2, > + .rate_min = 8000, > + .rate_max = 192000, > + }, > + .id = USB_RX, > + .name = "USB_RX", > + }, Wait, is this saying you will have exactly one PCM device/FE DAI connected to the USB BE DAI exposed in patch 11? > + SND_SOC_DAPM_MIXER("USB Mixer", SND_SOC_NOPM, 0, 0, > + usb_mixer_controls, > + ARRAY_SIZE(usb_mixer_controls)), > + And then what is the role of the USB mixer if you only have one input? I must be missing something.