Re: [PATCH v21 09/39] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

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.