Re: [PATCH] PCI: ACPI: Fix ThunderX PEM initialization

[Bjorn Helgaas]

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.

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 :)

Bjorn