Hello, > @@ -1749,10 +1767,13 @@ static umode_t pcie_dev_attrs_are_visible(struct kobject *kobj, > struct device *dev = kobj_to_dev(kobj); > struct pci_dev *pdev = to_pci_dev(dev); > > - if (pci_is_pcie(pdev)) > - return a->mode; > + if (!pci_is_pcie(pdev)) > + return 0; > > - return 0; > + if (a == &dev_attr_serial_number.attr && !pci_get_dsn(pdev)) > + return 0; > + > + return a->mode; It would be fine to have this sysfs attribute present all the time, and simply return error when the serial number is not available. Not sure if hiding it adds a lot of value. This is how some of the existing attributes currently behave. But it does add extra code to pcie_dev_attrs_are_visible() where it is now a special case, somewhat. Thank you, Krzysztof
