Re: [PATCH] ACPI: processor: idle: Reset power_setup_done flag on initialization failure

[Rafael J. Wysocki]

On Fri, Apr 3, 2026 at 10:53 AM Huisong Li <lihuisong@xxxxxxxxxx> wrote:
>
> The 'power_setup_done' flag is a key indicator used across the ACPI
> processor driver to determine if cpuidle are properly configured and
> available for a given CPU.
>
> Currently, this flag is set during the early stages of initialization.
> However, if the subsequent registration of the cpuidle driver in
> acpi_processor_register_idle_driver() or the per-CPU device registration
> in acpi_processor_power_init() fails, this flag remains set. This may
> lead to some issues where other functions in ACPI idle driver use these
> flags.
>
> Fix this by explicitly resetting this flag to 0 in these error paths.
>
> Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> ---
>  drivers/acpi/processor_idle.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 2adaee0f32ed..c1cddb4a5887 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1378,6 +1378,7 @@ void acpi_processor_register_idle_driver(void)
>
>         ret = cpuidle_register_driver(&acpi_idle_driver);
>         if (ret) {
> +               pr->flags.power_setup_done = 0;
>                 pr_debug("register %s failed.\n", acpi_idle_driver.name);
>                 return;
>         }
> @@ -1386,7 +1387,16 @@ void acpi_processor_register_idle_driver(void)
>
>  void acpi_processor_unregister_idle_driver(void)
>  {
> +       struct acpi_processor *pr;
> +       int cpu;
> +
>         cpuidle_unregister_driver(&acpi_idle_driver);
> +       for_each_possible_cpu(cpu) {
> +               pr = per_cpu(processors, cpu);
> +               if (!pr)
> +                       continue;
> +               pr->flags.power_setup_done = 0;
> +       }
>  }
>
>  void acpi_processor_power_init(struct acpi_processor *pr)
> @@ -1423,6 +1433,7 @@ void acpi_processor_power_init(struct acpi_processor *pr)
>          */
>         if (cpuidle_register_device(dev)) {
>                 per_cpu(acpi_cpuidle_device, pr->id) = NULL;
> +               pr->flags.power_setup_done = 0;
>                 kfree(dev);
>         }
>  }
> --

Applied as 7.1 material, thanks!