PCI_MAX_LAT
pci_write_config_byte(dev, PCI_MAX_LAT, 0x08);
pci_write_config_byte(dev, PCI_MAX_LAT, 0x08);
pci_write_config_byte(dev, PCI_MAX_LAT, 0x08);
pci_read_config_byte(dev, PCI_MAX_LAT, &limit);