On Mon, Aug 29, 2022 at 6:29 PM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
>
> On some platforms it is found that Linux more aggressively enters s2idle
> than Windows enters Modern Standby and this uncovers some synchronization
> issues for the platform. To aid in debugging this class of problems in
> the future, add support for an extra optional callback intended for
> drivers to emit extra debugging.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
and I'm assuming that this is for Hans.
> ---
> v2->v3:
> * Rename to *check
> v1->v2:
> * Add a prototype for `acpi_s2idle_enter`
>
> drivers/acpi/sleep.h | 1 +
> drivers/acpi/x86/s2idle.c | 14 ++++++++++++++
> include/linux/acpi.h | 1 +
> include/linux/suspend.h | 1 +
> kernel/power/suspend.c | 3 +++
> 5 files changed, 20 insertions(+)
>
> diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
> index 7fe41ee489d6..d960a238be4e 100644
> --- a/drivers/acpi/sleep.h
> +++ b/drivers/acpi/sleep.h
> @@ -18,6 +18,7 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
> extern int acpi_s2idle_begin(void);
> extern int acpi_s2idle_prepare(void);
> extern int acpi_s2idle_prepare_late(void);
> +extern void acpi_s2idle_check(void);
> extern bool acpi_s2idle_wake(void);
> extern void acpi_s2idle_restore_early(void);
> extern void acpi_s2idle_restore(void);
> diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
> index f9ac12b778e6..474aa46f82f6 100644
> --- a/drivers/acpi/x86/s2idle.c
> +++ b/drivers/acpi/x86/s2idle.c
> @@ -486,6 +486,19 @@ int acpi_s2idle_prepare_late(void)
> return 0;
> }
>
> +void acpi_s2idle_check(void)
> +{
> + struct acpi_s2idle_dev_ops *handler;
> +
> + if (!lps0_device_handle || sleep_no_lps0)
> + return;
> +
> + list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
> + if (handler->check)
> + handler->check();
> + }
> +}
> +
> void acpi_s2idle_restore_early(void)
> {
> struct acpi_s2idle_dev_ops *handler;
> @@ -527,6 +540,7 @@ static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
> .begin = acpi_s2idle_begin,
> .prepare = acpi_s2idle_prepare,
> .prepare_late = acpi_s2idle_prepare_late,
> + .check = acpi_s2idle_check,
> .wake = acpi_s2idle_wake,
> .restore_early = acpi_s2idle_restore_early,
> .restore = acpi_s2idle_restore,
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 6f64b2f3dc54..acaa2ddc067d 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -1075,6 +1075,7 @@ acpi_status acpi_os_prepare_extended_sleep(u8 sleep_state,
> struct acpi_s2idle_dev_ops {
> struct list_head list_node;
> void (*prepare)(void);
> + void (*check)(void);
> void (*restore)(void);
> };
> int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg);
> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
> index 70f2921e2e70..03ed42ed2c7f 100644
> --- a/include/linux/suspend.h
> +++ b/include/linux/suspend.h
> @@ -191,6 +191,7 @@ struct platform_s2idle_ops {
> int (*begin)(void);
> int (*prepare)(void);
> int (*prepare_late)(void);
> + void (*check)(void);
> bool (*wake)(void);
> void (*restore_early)(void);
> void (*restore)(void);
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index 827075944d28..c6272d466e58 100644
> --- a/kernel/power/suspend.c
> +++ b/kernel/power/suspend.c
> @@ -136,6 +136,9 @@ static void s2idle_loop(void)
> break;
> }
>
> + if (s2idle_ops && s2idle_ops->check)
> + s2idle_ops->check();
> +
> s2idle_enter();
> }
>
> --
> 2.34.1
>
