> +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?