Re: [PATCH v24 19/34] ASoC: qcom: qdsp6: Fetch USB offload mapped card and PCM device

+static int q6usb_get_offload_dev(struct snd_soc_component *component,

• 		 int card, int pcm, enum snd_soc_usb_kctl route)
  

+{

• struct q6usb_port_data *data = dev_get_drvdata(component->dev);
• struct snd_soc_usb_device *sdev;
• int ret = -1;
• mutex_lock(&data->mutex);
• if (list_empty(&data->devices))

• goto out;
  

• sdev = list_last_entry(&data->devices, struct snd_soc_usb_device, list);
• if ((card == sdev->card_idx) && (pcm == sdev->pcm_idx)) {

• if (route == SND_SOC_USB_KCTL_CARD_ROUTE)
  

• 	ret = component->card->snd_card->number;
  

• else if (route == SND_SOC_USB_KCTL_PCM_ROUTE)
  

• 	ret = q6usb_get_pcm_id(component);
  

• }

+out:

• mutex_unlock(&data->mutex);
• return ret;

+}

well I obviously didn't get how this function worked until now, it's supposed to be call TWICE with a different argument.

Not sure it's really wise with the locking, why not get both in one shot?

Also how does this update the kcontrol value?