SLEEP_SLOP
(bs->bs_sleepduration - SLEEP_SLOP) << 3);
SM((nextdtim - SLEEP_SLOP) << 3, AR_SLEEP1_NEXT_DTIM)
SM((nextTbtt - SLEEP_SLOP) << 3, AR_SLEEP2_NEXT_TIM)
TU_TO_USEC(bs->bs_nextdtim - SLEEP_SLOP));
OS_REG_WRITE(ah, AR_NEXT_TIM, TU_TO_USEC(nextTbtt - SLEEP_SLOP));