Re: [PATCH] cxl/acpi: Warn on unsupported platform config detection

From: Fabio M. De Francesco
Date: Wed Jun 26 2024 - 06:37:22 EST


On Wednesday, June 26, 2024 2:45:14 AM GMT+2 Dan Williams wrote:
> Alison Schofield wrote:
> > On Wed, Jun 19, 2024 at 02:59:41PM +0200, Fabio M. De Francesco wrote:
> >
> > Fabio,
> >
> > cxl/acpi does a lot of platform config work. "...unsupported platform
> > config detection" gives no hint that this is about CHBS's or an eRCD.
> > Please offer something more specific. Thanks.
>
> The message specifies "mixed Virtual Host and Restricted CXL Host
> hierarchy" as the conflict. The relationship between RCH and eRCDs is an
> exercise for the reader, and CHBS is an ACPI detail that really should
> not be emitted in an error message. So I am struggling to imagine what a
> more specific error message would be without paragraphs of backstory.
>
> All that is needed here is just enough words for when someone posts a
> problem to the list that someone savvy can go "ah, you fell into this
> specification hole where CXL 2.0 root port registers are difficult to
> associate with an RCH config, thanks for the report now we know that
> Linux needs to worry about this case".
>
I think that Alison raised a good point.

If you have nothing against it, I'll change the subject line to: "cxl/acpi:
Warn on mixed VH and eRCH hierarchies"

How about that change?

Fabio