[RFC PATCH v4 2/8] cpuidle: Change :enter_dead() driver callback return type to void

From: Patryk Wlazlyn
Date: Mon Nov 25 2024 - 08:21:27 EST


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>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/acpi/processor_idle.c | 7 ++-----
include/linux/cpuidle.h | 2 +-
2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 831fa4a12159..ce728cf7e301 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -578,7 +578,7 @@ static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
* @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 cpuidle_device *dev, int index)
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)
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 3183aeb7f5b4..a9ee4fe55dcf 100644
--- a/include/linux/cpuidle.h
+++ b/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
--
2.47.0