AR_INTR_ASYNC_CAUSE
if (REG_READ(ah, AR_INTR_ASYNC_CAUSE(ah)) & AR_INTR_MAC_IRQ) {
async_cause = REG_READ(ah, AR_INTR_ASYNC_CAUSE(ah));
host_isr = REG_READ(ah, AR_INTR_ASYNC_CAUSE(ah));