AGP_AMD751_APCTRL
vas = (pci_read_config(dev, AGP_AMD751_APCTRL, 1) & 0x06) >> 1;
pci_write_config(dev, AGP_AMD751_APCTRL,
(((pci_read_config(dev, AGP_AMD751_APCTRL, 1) & ~0x06)