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

[Sinan Kaya <okaya@kernel.org>]

On 11/19/2018 11:53 AM, Keith Busch wrote:
> 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@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.
> 

I don't see *any* in the code.  aer_hest_parse() does the HEST table parsing.
It switches to firmware first mode if global flag in HEST is set. Otherwise
for each BDF in device, hest_match_pci() is used to do a cross-matching against
HEST table contents.

Am I missing something?