RCAR_DRIF_BUF_OVERFLOW
return ((buf[0]->status | buf[1]->status) & RCAR_DRIF_BUF_OVERFLOW);
ch->buf[idx].status |= RCAR_DRIF_BUF_OVERFLOW;
rcar_drif_bufs_clear(buf, RCAR_DRIF_BUF_OVERFLOW);
if (buf[0]->status & RCAR_DRIF_BUF_OVERFLOW) {
buf[0]->status &= ~RCAR_DRIF_BUF_OVERFLOW;