>> 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.
>>
>
> Not sure if this is a QCOM specific implementation, but the way the DT
> is defined for the USB offload path is as follows:
>
> usb-dai-link {
> link-name = "USB Playback";
>
> cpu {
> sound-dai = <&q6afedai USB_RX>;
> };
>
> codec {
> sound-dai = <&usbdai USB_RX>;
> };
>
> platform {
> sound-dai = <&q6routing>;
> };
> };
>
> Based on our DT parser helper API (qcom_snd_parse_of()) this isn't going
> to create a PCM device. The PCM devices are created for nodes that
> don't have a codec and platform defined:
>
> mm1-dai-link {
> link-name = "MultiMedia1";
> cpu {
> sound-dai = <&q6asmdai MSM_FRONTEND_DAI_MULTIMEDIA1>;
> };
> };
>
> The ASM path is the entity that defines the number of PCM devices that
> is created for the QC ASoC platform card, and is where the actual PCM
> data is sent over to the DSP. So there could be several PCM devices
> that can use the USB BE DAI.
ok, but then how would this work with the ALSA controls reporting which
PCM device can be used? I didn't see a mechanism allowing for more than
one offloaded device, IIRC the control reported just ONE PCM device number.
