AHCI_BOHC
((v = ATA_INL(ctlr->r_mem, AHCI_BOHC)) & AHCI_BOHC_OOS) == 0) {
ATA_OUTL(ctlr->r_mem, AHCI_BOHC, v | AHCI_BOHC_OOS);
v = ATA_INL(ctlr->r_mem, AHCI_BOHC);