XLNX_IRQ_FLAG_USED
if (sc->isrcs[end_irq].flags & XLNX_IRQ_FLAG_USED) {
sc->isrcs[irq + i].flags |= XLNX_IRQ_FLAG_USED;
KASSERT(xi->flags & XLNX_IRQ_FLAG_USED,
xi->flags &= ~XLNX_IRQ_FLAG_USED;