IVTV_MBOX_DRIVER_BUSY
write_sync(IVTV_MBOX_DRIVER_BUSY, &mbdata->mbox[mb].flags);
write_sync(IVTV_MBOX_DRIVER_DONE | IVTV_MBOX_DRIVER_BUSY, &mbox->flags);
wrData[0] = IVTV_MBOX_DRIVER_DONE|IVTV_MBOX_DRIVER_BUSY;