PCI_EXP_DEVCAP_FLR
if (!(reg & PCI_EXP_DEVCAP_FLR))
value &= ~PCI_EXP_DEVCAP_FLR;
if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
if (!ret && (cap & PCI_EXP_DEVCAP_FLR)) {