On Wed, Apr 20, 2022 at 3:44 PM Ville Syrjala
<ville.syrjala@xxxxxxxxxxxxxxx> wrote:
>
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> commit d6b88ce2eb9d ("ACPI: processor idle: Allow playing dead in C3 state")
> was supposedly just trying to enable C3 when the CPU is offlined,
> but it also mistakenly enabled C3 usage without setting ARB_DIS=1
> in normal idle scenarios.
>
> This results in a machine that won't boot past the point when it first
> enters C3. Restore the correct behaviour (either demote to C1/C2, or
> use C3 but also set ARB_DIS=1).
>
> I hit this on a Fujitsu Siemens Lifebook S6010 (P3) machine.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Woody Suwalski <wsuwalski@xxxxxxxxx>
> Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
> Cc: Richard Gong <richard.gong@xxxxxxx>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Fixes: d6b88ce2eb9d ("ACPI: processor idle: Allow playing dead in C3 state")
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/acpi/processor_idle.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 4556c86c3465..54f0a1915025 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -793,10 +793,10 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr)
>
> state->flags = 0;
> if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 ||
> - cx->type == ACPI_STATE_C3) {
> + cx->type == ACPI_STATE_C3)
> 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
> --
Good catch, but I would prefer doing the below which should be
equivalent (modulo GMail-induced white space breakage):
---
drivers/acpi/processor_idle.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -795,7 +795,8 @@ static int acpi_processor_setup_cstates(
if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2 ||
cx->type == ACPI_STATE_C3) {
state->enter_dead = acpi_idle_play_dead;
- drv->safe_state_index = count;
+ if (cx->type != ACPI_STATE_C3)
+ drv->safe_state_index = count;
}
/*
* Halt-induced C1 is not good for ->enter_s2idle, because it
