AHCI_P_TFD
tfd = AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel));
AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel))),
tfd = AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel));
tfd = AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel));
sig = AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel));