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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 11 Oct 2019 12:38:49 +0200
Message-ID: <CAJZ5v0ioC6XnC+sFpRJmm40T+YCnqoaHhJ+_Pmk7rvvC8UPT9w@mail.gmail.com>
Subject: Re: [PATCH 1/2] acpi: Fail GED probe when not on hardware-reduced
To:     Samuel Ortiz <sameo@linux.intel.com>
Cc:     Len Brown <lenb@kernel.org>,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>
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On Wed, Oct 9, 2019 at 3:04 PM Samuel Ortiz <sameo@linux.intel.com> wrote:
>
> The Generic Event Device (GED) is a hardware-reduced platform device.

No, it is not AFAICS.

The spec doesn't say that GED cannot be used on platforms that aren't
HW-reduced and if evged.c is going to be built in unconditionally, the
kernel will be able to handle GED regardless.

> Probing this driver on fixed platforms should fail.
>
> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> ---
>  drivers/acpi/evged.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
> index aba0d0027586..55de4b2d2fee 100644
> --- a/drivers/acpi/evged.c
> +++ b/drivers/acpi/evged.c
> @@ -127,6 +127,9 @@ static int ged_probe(struct platform_device *pdev)
>         struct acpi_ged_device *geddev;
>         acpi_status acpi_ret;
>
> +       if (!acpi_gbl_reduced_hardware)
> +               return -ENODEV;
> +
>         geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL);
>         if (!geddev)
>                 return -ENOMEM;
> --
> 2.21.0
>