AGP_INTEL_NBXCFG
pci_write_config(dev, AGP_INTEL_NBXCFG,
(pci_read_config(dev, AGP_INTEL_NBXCFG, 4)
reg = pci_read_config(dev, AGP_INTEL_NBXCFG, 4) & ~(1 << 9);
pci_write_config(dev, AGP_INTEL_NBXCFG, reg, 4);