RTW_TNPDA
RTW_WRITE(regs, RTW_TNPDA, RTW_RING_BASE(phybaseaddr, hd_txmd));
rsc->hw_start = RTW_READ(regs, RTW_TNPDA);
rsc->hw_go = RTW_READ(regs, RTW_TNPDA);
head = RTW_READ(&rsc->sc_regs, RTW_TNPDA);
PRINTREG32(regs, RTW_TNPDA);