SNDRV_MIXER_OSS_PRESENT_CSWITCH
if (slot.present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {
if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH)
} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_CSWITCH) {