On Wed, May 11, 2016 at 09:22:03PM -0600, Alex Williamson wrote: [...] > PCI Express to PCI/PCI-X Bridge Specification rev 1.0 > 2.3 Assignment of Requester ID and Tag by the Bridge > > PCIe-to-PCI bridges assign a requester ID composed of the secondary bus > number with devfn = 0. Although often on real hardware, the root > complex PCI bridge uses the actual bridge requester ID even though > it's actually a PCIe bridge. Linux assume that if a bridge has a PCIe > capability with type PCIe-to-PCI/X bridge we use the secondary bus > requester ID, if it has a PCIe capability with type PCI/X-to-PCIe, we > use the bridge requester ID. If it does not have a PCIe capability we > use the bridge ID except for a few quirked devices known to use the > secondary bus ID. Yay standards! Thanks,
Thanks Alex! I have found pci and pci-to-pci bridge specs, which seems useful to me. However, I still cannot find pcie-to-pci bridge spec online (as you have mentioned above). Is that only for registered users? -- peterx
