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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Thu, 14 Nov 2019 09:49:59 +0100
Message-ID: <CAJZ5v0j4c8o9Tnex0fcnkmTMazSGPmVPiQf1C4kqE_yLUyMz9A@mail.gmail.com>
Subject: Re: [PATCH v2] ACPI: sysfs: Change ACPI_MASKABLE_GPE_MAX to 0x100
To:     Yunfeng Ye <yeyunfeng@huawei.com>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        "hushiyuan@huawei.com" <hushiyuan@huawei.com>,
        "linfeilong@huawei.com" <linfeilong@huawei.com>
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On Thu, Nov 14, 2019 at 8:16 AM Yunfeng Ye <yeyunfeng@huawei.com> wrote:
>
> The commit 0f27cff8597d ("ACPI: sysfs: Make ACPI GPE mask kernel
> parameter cover all GPEs") says:
>   "Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256
>    GPEs can be masked"
>
> But the masking of GPE 0xFF it not supported and the check condition
> "gpe > ACPI_MASKABLE_GPE_MAX" is not valid because the type of gpe is
> u8.
>
> So modify the macro ACPI_MASKABLE_GPE_MAX to 0x100, and drop the "gpe >
> ACPI_MASKABLE_GPE_MAX" check. In addition, update the docs "Format" for
> acpi_mask_gpe parameter.
>
> Fixes: 0f27cff8597d ("ACPI: sysfs: Make ACPI GPE mask kernel parameter cover all GPEs")
> Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>

Applying as 5.5 material, thanks!

> ---
> v1 -> v2:
>  - drop the "gpe > ACPI_MASKABLE_GPE_MAX" check
>  - update the docs "Format" from <int> to <byte> for acpi_mask_gpe parameter
>  - update the commit comment
>
>  Documentation/admin-guide/kernel-parameters.txt | 2 +-
>  drivers/acpi/sysfs.c                            | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a84a83f8881e..87e27186dc69 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -113,7 +113,7 @@
>                         the GPE dispatcher.
>                         This facility can be used to prevent such uncontrolled
>                         GPE floodings.
> -                       Format: <int>
> +                       Format: <byte>
>
>         acpi_no_auto_serialize  [HW,ACPI]
>                         Disable auto-serialization of AML methods
> diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
> index 75948a3f1a20..0a83ce186bc4 100644
> --- a/drivers/acpi/sysfs.c
> +++ b/drivers/acpi/sysfs.c
> @@ -819,14 +819,14 @@ static ssize_t counter_set(struct kobject *kobj,
>   * interface:
>   *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
>   */
> -#define ACPI_MASKABLE_GPE_MAX  0xFF
> +#define ACPI_MASKABLE_GPE_MAX  0x100
>  static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
>
>  static int __init acpi_gpe_set_masked_gpes(char *val)
>  {
>         u8 gpe;
>
> -       if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
> +       if (kstrtou8(val, 0, &gpe))
>                 return -EINVAL;
>         set_bit(gpe, acpi_masked_gpes_map);
>
> --
> 2.7.4
>