On Tue, Apr 03, 2018 at 04:31:15PM +0200, Rafael J. Wysocki wrote: > On Tue, Apr 3, 2018 at 4:16 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > > This picture doesn't make sense to me yet. Per the PCI Firmware spec, > > r3.2, sec 4.5.2, we use _OSC to negotiate control over AER (and now > > DPC). I think _OSC is only allowed directly under a host bridge > > device (PNP0A08 or PNP0A03), and it applies to the entire hierarchy > > under the host bridge. > > > > I don't know how firmware could claim to own AER on a root port, but > > not on switches (external or otherwise) below that root port. > > > > If _OSC says firmware owns AER, we won't touch AER on the root port, > > but we also won't touch DPC on switches below the root port. So I > > don't see how this change will help. > > This matches my understanding of that part of the spec. Thanks, guys. It seems this patch doesn't accomplish anything.
