Re: [RFC PATCH 03/14] ASoC: qcom: Add USB backend ASoC driver for Q6

Wesley Cheng
2023-01-06T01:07:27Z

Hi Pierre,

On 1/4/2023 3:41 PM, Pierre-Louis Bossart wrote:
>
>> +int q6usb_alsa_connection_cb(struct snd_soc_usb *usb, int card_idx,
>> + int connected)
>> +{
>> + struct snd_soc_dapm_context *dapm;
>> + struct q6usb_port_data *data;
>> +
>> + if (!usb->component)
>> + return 0;
>> +
>> + dapm = snd_soc_component_get_dapm(usb->component);
>> + data = dev_get_drvdata(usb->component->dev);
>> +
>> + if (connected) {
>> + snd_soc_dapm_enable_pin(dapm, "USB_RX_BE");
>> + /* We only track the latest USB headset plugged in */
>
> that answers to my earlier question on how to deal with multiple
> devices, but is this a desirable policy? This could lead to a lot of
> confusion. If there are restrictions to a single device, then it might
> be more interesting for userspace or the user to indicate which USB
> device gets to use USB offload and all others use legacy.
>

Yeah, as mentioned its still pretty open ended. I think from the
feedback received from Mark/Takashi, this was a viable option for now.
Would you happen to have any insight/input on how the userspace can pass
down that selection to the ASoC framework? Maybe some kind of PCM IOCTL
call?

Thanks
Wesley Cheng