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> > - if (pci_bus_rrs_vendor_id(*l)) > + if (pci_bus_rrs_vendor_id(*l)) { > + /* > + * RRS (Request Retry Status) is a PCIe link-layer mechanism > + * where a downstream device sends a RRS completion status, and the > + * Root Port (with RRS Software Visibility enabled) translates > + * it to Vendor ID 0x0001 for the driver, indicating the > + * device is not ready. > + * > + * Therefore, RRS is a root port feature, and devices on the root bus, > + * for example the root port itself have no upstream PCIe link, > + * so they can never legitimately return RRS. > + */ > + if (pci_is_root_bus(bus)) { > + pr_err("pci %04x:%02x:%02x.%d: invalid Vendor ID %04x (RRS, reserved by PCI SIG) on root bus, buggy device\n", > + pci_domain_nr(bus), bus->number, > + PCI_SLOT(devfn), PCI_FUNC(devfn), > + *l & 0xffff); > + return false; > + } > return pci_bus_wait_rrs(bus, devfn, l, timeout); > + } > > return true; > } >