p50_wait_ec
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
ret = p50_wait_ec(p50, P50_STATUS_OBF, P50_STATUS_OBF);
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);
ret = p50_wait_ec(p50, P50_STATUS_IBF, 0);