Re: [PATCH v2 1/3] PCI: Add check for CXL Secondary Bus Reset

Jonathan Cameron
2024-04-03T14:44:45Z

On Tue, 2 Apr 2024 10:46:08 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> Bjorn Helgaas wrote:
> [..]
> > FWIW, I pinged administration@pcisig.com and got the response that
> > "1E98h is not a VID in our system, but 1E98 has already been reserved
> > by CXL."
> >
> > I wish there were a clearer public statement of this reservation, but
> > I interpret the response to mean that CXL is not a "Vendor", maybe due
> > to some strict definition of "Vendor," but that PCI-SIG will not
> > assign 0x1e98 to any other vendor.
> >
> > So IMO we should add "#define PCI_VENDOR_ID_CXL 0x1e98" so that if we
> > ever *do* see such an assignment, we'll be more likely to flag it as
> > an issue.
>
> Agree.

Sorry for late entry on this discussion and I'll be careful what I say
on the history.

As you've guessed it was "entertaining" and for FWIW that text occurs
in other consortium specs (some predate CXL).

It's reserved with agreement from the PCI SIG for a strictly defined set
of purposes that does not correspond to those allowed for a normal ID
granted to a vendor member. As you say CXL isn't a vendor (don't ask
how DMTF got a vendor ID - 0x1AB4).

Hence the naming gymnastics and vague answers to avoid any chance of
lawyers getting involved :(

Jonathan