CONF2_ENABLE_PORT
outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
outb(CONF2_ENABLE_PORT, 0);
oldval2 = inb(CONF2_ENABLE_PORT);
outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
mode2res = inb(CONF2_ENABLE_PORT);
outb(CONF2_ENABLE_PORT, oldval2);