On Friday 21 January 2022 15:51:34 Martin Mareš wrote: > Hello! > > > Extend libpci API with a new option PCI_FILL_PARENT to fill parent > > device for the current enumerated device. This can be useful in > > situation when non-complaint PCI-to-PCI bridge-like device with Type 0 > > header is present in the system and behind this bridge are either > > endpoint devices or another non-compliant bridges. This applies e.g. > > for notoriously broken Galileo and Marvell PCI and PCIe devices. > > lspci can will use PCI_FILL_PARENT information from the system if > > config space does not provide enough information to build topology. > > Looks reasonable, but please put a better explanation in pci.h > (in particular, mention that this is not guaranteed to be available). Ok! > When reading the implementation in the sysfs backend, I wonder how you > can guarantee that at the moment of parsing the child device, the parent > device is already known to libpci. All devices are parsed in sysfs_scan() function. And additional information, including this "parent" is filled in sysfs_fill_info() function. sysfs_scan() itself does not call sysfs_fill_info(). So prior calling pci_fill_info() it is required to call pci_scan_bus() to have ->parent member filled.
