On 11/19/2024 09:09, Gautham R. Shenoy wrote:
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>
Reviewed-by: Mario Limonciello <mario.limonciello@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)
