HPC1_HDD_CTL_INTR
sc->sc_txdesc[lasttx].hpc1_hdd_ctl |= HPC1_HDD_CTL_INTR;
&= ~HPC1_HDD_CTL_INTR;
HPC1_HDD_CTL_INTR | HPC1_HDD_CTL_EOPACKET;