From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sinan Kaya Subject: Re: [PATCH 0/2] PCI/AER: Consistently use _OSC to determine who owns AER Date: Mon, 19 Nov 2018 20:54:21 -0500 Message-ID: <3b18a9fa-7bdd-0fb4-285d-4efb454be50a@kernel.org> References: <20181115231605.24352-1-mr.nuke.me@gmail.com> <20181119165318.GB26595@localhost.localdomain> <74f2c527-0890-5e14-5e2d-48934a42dae6@kernel.org> <20181119174127.GE26595@localhost.localdomain> <20181119181051.GA26707@localhost.localdomain> <3f923367-2cc1-c0d6-bca6-bf9a03d1b9ca@gmail.com> <84013a8a-287d-d700-6710-91cc35f507c8@kernel.org> <9c9531c7efb846438f03f744b9afc466@ausx13mps321.AMER.DELL.COM> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9c9531c7efb846438f03f744b9afc466@ausx13mps321.AMER.DELL.COM> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Alex_Gagniuc@Dellteam.com, mr.nuke.me@gmail.com, keith.busch@intel.com Cc: baicar.tyler@gmail.com, Austin.Bolen@dell.com, Shyam.Iyer@dell.com, lukas@wunner.de, bhelgaas@google.com, rjw@rjwysocki.net, lenb@kernel.org, ruscur@russell.cc, sbobroff@linux.ibm.com, oohall@gmail.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: linux-acpi@vger.kernel.org On 11/19/2018 6:49 PM, Alex_Gagniuc@Dellteam.com wrote: > On 11/19/2018 02:33 PM, Sinan Kaya wrote: >> However; table assumes governance about for which entities firmware first >> should be enabled. There is no cross reference to _OSC or permission >> negotiation like _OST. > > Well, from an OSPM perspective, is FFS something that can be enabled or > disabled? FFS seems to be static to OSPM, which would change the sort of > assumptions we can reasonably make here. IMO, it can be enabled/disabled in BIOS. I have seen this implementation before. If the trigger is the presence of a statically compiled ACPI HEST table (as the current code does); presence of FFS would be static from OSPM perspective. BIOS could patch this table or hide it during boot. If FFS were to be negotiated via _OSC as indirectly implied in this series, then same BIOS could patch the ACPI table to return different values for the _OSC return. > > >>>> As I said in my previous email, the right place to talk about this is UEFI >>>> forum. >>> >>> The way I would present the problem to he spec writers is that, although >>> the spec appears to be consistent, we've seen firmware vendors that made >>> the wrong assumptions about HEST/_OSC. Instead of describing AER >>> ownership with _OSC, they attempted to do it with HEST. So we should add >>> an implementation note, or clarification about this. >> >> I agree. > > Cool. While the UEFI Secret Society debates, can we figure out if/how > [patch 1/2] breaks those systems, or is it only [patch 2/2] of this > series that we suspect? I went back and looked at both patches. Both of them are removing references to HEST table. I think both patches are impacted by this discussion. > > Alex >