ID_BIT_AUDIO
#define client_is_audio(c) ((c)->id & ID_BIT_AUDIO)
#define client_id(c) ((c)->id & ~ID_BIT_AUDIO)
return register_client(pdev, ops, id | ID_BIT_AUDIO, false, false);
client = find_client_from_id(&vgasr_priv->clients, id | ID_BIT_AUDIO);