Subject: Re: [PATCH] PCI: ACPI: Fix ThunderX PEM initialization
To: Bjorn Helgaas <helgaas@kernel.org>, Jon Masters <jcm@jonmasters.org>
References: <20170131142525.GA9942@bhelgaas-glaptop.roam.corp.google.com>
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 <376ae1df-da85-e576-75d6-3ae2ab0f1b41@jonmasters.org>
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 <20170321134744.GA13150@bhelgaas-glaptop.roam.corp.google.com>
Cc: David Daney <ddaney.cavm@gmail.com>,
        Vadim Lomovtsev <Vadim.Lomovtsev@caviumnetworks.com>,
        David.Daney@cavium.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        stemerkhanov@CAVIUMNETWORKS.onmicrosoft.com, bhelgaas@google.com,
        linux-arm-kernel@lists.infradead.org
From: Tomasz Nowicki <tn@semihalf.com>
Message-ID: <b50b6a7f-30be-4206-4f38-2539ea936228@semihalf.com>
Date: Tue, 21 Mar 2017 15:17:17 +0100
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Hi Bjorn,

On 21.03.2017 14:47, Bjorn Helgaas wrote:
> On Tue, Mar 21, 2017 at 07:38:07AM -0400, Jon Masters wrote:
>> On 03/16/2017 12:25 PM, David Daney wrote:
>>> On 03/16/2017 07:32 AM, Jon Masters wrote:
>>
>>>>> Yes, it is now contains "CAVxxx" as _HID for device config object.
>>>>
>>>> Which is different from the version that was merged into upstream. That
>>>> should never have happened. It will never happen again. I have spent some
>>>> time over the past few days ensuring folks understand that I will not
>>>> allow a repeat of this to occur the next time around. We will have
>>>> platforms that are bulletproof and supported by upstream with any
>>>> errata fixes in a very carefully controlled manner. There will
>>>> under no circumstances ever be a situation like this again.
>>>
>>> We are still evaluating the merits of registering the values that appeared
>>> in v4.10, and not changing them.  We should know more in a couple of days.
>>
>> Thanks David. What was the verdict? (for the public record). If we need to
>> get a change into upstream, let's get that teed up before 4.12 merge.
>>
>> And for other folks following along with this thread: I'm not just picking
>> on Cavium here. I'll be doing the same with *every* ARM server SoC company
>> as necessary over the coming months. We are going to have militantly
>> compliant standards adherence in this industry and every ARM server SoC is
>> going to "just work" with an upstream Linux kernel with an ACPI enabled
>> platform. This will be so utterly clean and boring it'll be amazing.
>
> Thanks for keeping on top of this, Jon.  I agree, we should not be
> using unregistered vendor prefixes, e.g., the "THRX" added by
> 44f22bd91e88 ("PCI: Add MCFG quirks for Cavium ThunderX pass2.x host
> controller").  I'm sorry I merged that without doing the due
> diligence.

Honestly, it is me who is responsible for this since I submitted the patch.

>
> I suspect the resolution will be to register "THRX".  If that doesn't
> happen, I'll propose reverting 44f22bd91e88, not because I want to
> break things, but only because I'm not personally in a position to do
> anything smarter.  So please propose a better solution that fits
> within the ACPI _HID/_CID model :)

I already submitted the patch to fix this. Please see:
https://patchwork.ozlabs.org/patch/739042/

Thanks,
Tomasz