linux-kernel - Re: [RFC PATCH v4 3/8] ACPI: processor_idle: Use acpi_idle_play

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Message-ID: <CAJZ5v0iD30S1EyfqtV1_RDrxTCDmgbOA60njkdWpNzmpEAGXhw@mail.gmail.com>
Date: Mon, 25 Nov 2024 14:24:36 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Patryk Wlazlyn <patryk.wlazlyn@...ux.intel.com>
Cc: x86@...nel.org, linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, 
	rafael.j.wysocki@...el.com, len.brown@...el.com, 
	artem.bityutskiy@...ux.intel.com, dave.hansen@...ux.intel.com, 
	peterz@...radead.org, tglx@...utronix.de, gautham.shenoy@....com
Subject: Re: [RFC PATCH v4 3/8] ACPI: processor_idle: Use acpi_idle_play_dead()
 for all C-states

On Mon, Nov 25, 2024 at 2:20 PM Patryk Wlazlyn
<patryk.wlazlyn@...ux.intel.com> wrote:
>
> From: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
>
> Notice that acpi_processor_setup_cstates() can set state->enter_dead to acpi_idle_play_dead() for all C-states unconditionally and remove the
> confusing C-state type check done before setting it.
>
> No intentional functional impact.
>
> Suggested-by: Peter Zijlstra <peterz@...radead.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Reviewed-by: Mario Limonciello <mario.limonciello@....com>
> Tested-by: Mario Limonciello <mario.limonciello@....com> # 6.12-rc7
> Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>

This already is in the queue of patches to be merged during the 6.13
merge window.

I gather that it has been included here for completeness.

> ---
>  drivers/acpi/processor_idle.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index ce728cf7e301..698897b29de2 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -800,12 +800,12 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr)
>                 state->enter = acpi_idle_enter;
>
>                 state->flags = 0;
> -               if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 ||
> -                   cx->type == ACPI_STATE_C3) {
> -                       state->enter_dead = acpi_idle_play_dead;
> -                       if (cx->type != ACPI_STATE_C3)
> -                               drv->safe_state_index = count;
> -               }
> +
> +               state->enter_dead = acpi_idle_play_dead;
> +
> +               if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2)
> +                       drv->safe_state_index = count;
> +
>                 /*
>                  * Halt-induced C1 is not good for ->enter_s2idle, because it
>                  * re-enables interrupts on exit.  Moreover, C1 is generally not
> --
> 2.47.0
>
>