On Tue, 14 Mar 2017, Andi Kleen wrote: > The other option is to simply make it unconditional. That would > be even simpler, but it is a bit more risky. Hmm, I suppose may > be worth trying to find out what Windows uses. If they get away > with MMCONFIG everywhere we should be too. >From the PCIe spec: The PCI 3.0 compatible Configuration Space can be accessed using either the mechanism defined in the PCI Local Bus Specification or the PCI Express Enhanced Configuration Access Mechanism (ECAM) described later in this section. Accesses made using either access mechanism are equivalent. The PCI Express Extended Configuration Space can only be accessed by using the ECAM. The 1.0 spec has a similar wording (s/3.0/2.3). Definitely the best way to go. Thanks, tglx
