Re: [PATCH] ACPI: s2idle: Add _Ixx GPE wake indicator support

[Rafael J. Wysocki (Intel)]

On Fri, Sep 4, 2026 at 9:38 AM Saranya Gopal <saranya.gopal@xxxxxxxxx> wrote:
>
> ACPI 6.6 defines _Ixx indicator objects under \_GPE to mark GPEs that
> should remain wake-enabled in s2idle without a _PRW association.
> To support them, add new function acpi_setup_ixx_gpes() that looks for
> _Ixx objects for all GPEs in the FADT 0/1 blocks and if it finds any, it
> marks the corresponding GPE as wake-capable, in which case the GPE is
> also enabled so long as it has a handler method because marking it as
> wake-capable causes acpi_update_all_gpes() to skip it. Since that only
> needs to be done if suspend-to-idle is enabled, make acpi_s2idle_setup()
> call that new function.
>
> For now, this is limited to x86 systems and it assumes that the GPEs
> with _Ixx will not cause spurious wakeups to occur while suspended.
>
> Signed-off-by: Saranya Gopal <saranya.gopal@xxxxxxxxx>

Applied as 7.4 material, thanks!

> ---
>  drivers/acpi/x86/s2idle.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
> index b6b1dd76a06b..ac49f9e75fae 100644
> --- a/drivers/acpi/x86/s2idle.c
> +++ b/drivers/acpi/x86/s2idle.c
> @@ -24,6 +24,31 @@
>
>  #ifdef CONFIG_SUSPEND
>
> +static void acpi_setup_ixx_gpes(void)
> +{
> +       acpi_handle gpe_root;
> +       unsigned int i;
> +       char gpe_nr_str[5];
> +
> +       if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_GPE", &gpe_root)))
> +               return;
> +
> +       for (i = 0; i <= 0xff; i++) {
> +               scnprintf(gpe_nr_str, sizeof(gpe_nr_str), "_I%02X", i);
> +               if (!acpi_has_method(gpe_root, gpe_nr_str))
> +                       continue;
> +               /*
> +                * Enable the GPE if it has a handler method because marking it
> +                * as wake-capable causes acpi_update_all_gpes() to skip it.
> +                */
> +               if (ACPI_FAILURE(acpi_enable_gpe_cond(NULL, i, ACPI_GPE_DISPATCH_METHOD)))
> +                       continue;
> +               acpi_mark_gpe_for_wake(NULL, i);
> +               acpi_set_gpe_wake_mask(NULL, i, ACPI_GPE_ENABLE);
> +               pm_pr_dbg("ACPI: GPE 0x%02x armed for wake via %s\n", i, gpe_nr_str);
> +       }
> +}
> +
>  static bool sleep_no_lps0 __read_mostly;
>  module_param(sleep_no_lps0, bool, 0644);
>  MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
> @@ -649,6 +674,7 @@ void __init acpi_s2idle_setup(void)
>  {
>         acpi_scan_add_handler(&lps0_handler);
>         s2idle_set_ops(&acpi_s2idle_ops_lps0);
> +       acpi_setup_ixx_gpes();
>  }
>
>  int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
> --
> 2.34.1
>
>