Re: [PATCH v7 03/16] ACPI: processor: Drop duplicated check on _STA (enabled + present)

From: Rafael J. Wysocki
Date: Mon Apr 22 2024 - 14:51:09 EST


On Thu, Apr 18, 2024 at 3:55 PM Jonathan Cameron
<Jonathan.Cameron@xxxxxxxxxx> wrote:
>
> The ACPI bus scan will only result in acpi_processor_add() being called
> if _STA has already been checked and the result is that the
> processor is enabled and present. Hence drop this additional check.
>
> Suggested-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

LGTM, so

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
> v7: No change
> v6: New patch to drop this unnecessary code. Now I think we only
> need to explicitly read STA to print a warning in the ARM64
> arch_unregister_cpu() path where we want to know if the
> present bit has been unset as well.
> ---
> drivers/acpi/acpi_processor.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
> index 7fc924aeeed0..ba0a6f0ac841 100644
> --- a/drivers/acpi/acpi_processor.c
> +++ b/drivers/acpi/acpi_processor.c
> @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {}
> #ifdef CONFIG_ACPI_HOTPLUG_CPU
> static int acpi_processor_hotadd_init(struct acpi_processor *pr)
> {
> - unsigned long long sta;
> - acpi_status status;
> int ret;
>
> if (invalid_phys_cpuid(pr->phys_id))
> return -ENODEV;
>
> - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
> - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
> - return -ENODEV;
> -
> cpu_maps_update_begin();
> cpus_write_lock();
>
> --