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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 17 Nov 2020 13:45:20 -0800
Message-ID: <CAPcyv4i6MCu6RmLCyE+K-j3bbtrYeA+hJXL4+Zy_Tfhmwv2ErA@mail.gmail.com>
Subject: Re: [RFC PATCH 1/9] cxl/acpi: Add an acpi_cxl module for the CXL interconnect
To:     "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Ben Widawsky <ben.widawsky@intel.com>, linux-cxl@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PCI <linux-pci@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        "Kelley, Sean V" <sean.v.kelley@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
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On Tue, Nov 17, 2020 at 6:33 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
[..]
> > +static struct acpi_driver acpi_cxl_driver = {
>
> First of all, no new acpi_driver instances, pretty please!
>
> acpi_default_enumeration() should create a platform device with the
> ACPI0017 ID for you.  Can't you provide a driver for this one?
>

Ah, yes, I recall we had this discussion around the time the ACPI0012
NFIT driver was developed. IIRC the reason ACPI0012 remaining an
acpi_driver was due to a need to handle ACPI notifications, is that
the deciding factor? ACPI0017 does not have any notifications so it
seems like platform driver is the way to go.