[PATCH 0/2] PCI/AER: Consistently use _OSC to determine who owns AER

[Keith Busch]

On Mon, Nov 19, 2018 at 11:53:05AM -0500, Tyler Baicar wrote:
> On Thu, Nov 15, 2018 at 8:49 PM Sinan Kaya <okaya at kernel.org> wrote:
> >
> > On 11/15/2018 3:16 PM, Alexandru Gagniuc wrote:
> > > I've asked around a few people at Dell and they unanimously agree that
> > > _OSC is the correct way to determine ownership of AER. In linux, we
> > > use the result of _OSC to enable AER services, but we use HEST to
> > > determine AER ownership. That's inconsistent. This series drops the
> > > use of HEST in favor of _OSC.
> > >
> > > [1]https://lkml.org/lkml/2018/11/15/62
> >
> > This change breaks the existing systems that rely on the HEST table
> > telling the operating system about firmware first presence.
> >
> > Besides, HEST table has much more granularity about which PCI component
> > needs firmware such as global/device/switch.
> >
> > You should probably circulate these ideas for wider consumption in UEFI
> > forum as UEFI owns the HEST table definition.
> 
> I agree with Sinan, this will break existing systems, and the granularity of the
> HEST definition is more useful than the single bit in _OSC.

But we're not using HEST as a fine grain control. We disable native AER
handling if *any* device has FF set in HEST, and that just forces people
to use pcie_ports=native to get around that.