[QUESTION] Early Write Acknowledge for PCIe configuration space

Arnd Bergmann
2017-01-09T11:52:01Z

On Monday, January 9, 2017 10:59:47 AM CET John Garry wrote:
> On 06/01/2017 11:24, Arnd Bergmann wrote:
> > On Friday, January 6, 2017 11:15:22 AM CET John Garry wrote:
> >
> > Probably nobody thought about this properly in the Linux drivers. The
> > ARMv8 ARM sounds correct here.
> >
> > I/O space may have the same issue, as it also requires non-posted
> > accesses.
>
> Right, so our HW team's recommendation - from ARM's memory model and
> also PCIe order model - is that not only config space but also PCIe
> memory mapped IO has the same attribute (nE).

Just to be sure we are talking about the same thing: "PCIe memory
mapped IO" could refer to either PCI I/O space or PCI memory space.

As far as I can tell, PCI memory space should *not* be using the nE
attribute, while PCI I/O space and PCI config space should.
Does this match what your HW team recomments?

Arnd