Hello Rafael,
On Fri, Nov 15, 2024 at 10:00:25PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> After a previous change, cpuidle_play_dead(), which is the only caller
> of idle state :enter_dead() callbacks, ignores their return values, so
> they may as well be void.
>
> Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
>
> v1 -> v2: New patch
>
> Interestingly enough, the only user of :enter_dead() idle state callbacks
> in the current mainline turns out to be ACPI idle.
For that matter, the only user of cpuidle_play_dead() is the
native_play_dead(). Was that always the case?
Some of the other architectures select the deepest available idle
state at boot time, and enter that state when a CPU is offlined.
In any case I am ok with this.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
--
Thanks and Regards
gautham.
>
> ---
> drivers/acpi/processor_idle.c | 7 ++-----
> include/linux/cpuidle.h | 2 +-
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> Index: linux-pm/include/linux/cpuidle.h
> ===================================================================
> --- linux-pm.orig/include/linux/cpuidle.h
> +++ linux-pm/include/linux/cpuidle.h
> @@ -61,7 +61,7 @@ struct cpuidle_state {
> struct cpuidle_driver *drv,
> int index);
>
> - int (*enter_dead) (struct cpuidle_device *dev, int index);
> + void (*enter_dead) (struct cpuidle_device *dev, int index);
>
> /*
> * CPUs execute ->enter_s2idle with the local tick or entire timekeeping
> Index: linux-pm/drivers/acpi/processor_idle.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/processor_idle.c
> +++ linux-pm/drivers/acpi/processor_idle.c
> @@ -578,7 +578,7 @@ static void __cpuidle acpi_idle_do_entry
> * @dev: the target CPU
> * @index: the index of suggested state
> */
> -static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
> +static void acpi_idle_play_dead(struct cpuidle_device *dev, int index)
> {
> struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
>
> @@ -591,11 +591,8 @@ static int acpi_idle_play_dead(struct cp
> else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
> io_idle(cx->address);
> } else
> - return -ENODEV;
> + return;
> }
> -
> - /* Never reached */
> - return 0;
> }
>
> static __always_inline bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
>
>
>
