PL050 KMIDATA register does not reset

static uint32_t pl050_read(void *opaque, target_phys_addr_t offset){
  ...
   case 2: /* KMIDATA */
        if (s->pending)
            s->last = ps2_read_data(s->dev);
        return s->last;
}

When the receive queue is empty (s->pending is false), is the KMIDATA register supposed to be reset to 0x00? In the current implementation,  the  KMIDATA  does not reverse its value after interrupt is lowered.