PM: s2idle: ACPI: Fix wakeup interrupts handling

After commit e3728b50cd ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed.  Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.

The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop().  However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.

To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup.  Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one.  [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]

Fixes: e3728b50cd ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki
2022-02-04 18:35:22 +01:00
parent dc0075ba7f
commit cb1f65c1e1
6 changed files with 42 additions and 13 deletions

View File

@@ -497,14 +497,14 @@ extern void ksys_sync_helper(void);
/* drivers/base/power/wakeup.c */
extern bool events_check_enabled;
extern unsigned int pm_wakeup_irq;
extern suspend_state_t pm_suspend_target_state;
extern bool pm_wakeup_pending(void);
extern void pm_system_wakeup(void);
extern void pm_system_cancel_wakeup(void);
extern void pm_wakeup_clear(bool reset);
extern void pm_wakeup_clear(unsigned int irq_number);
extern void pm_system_irq_wakeup(unsigned int irq_number);
extern unsigned int pm_wakeup_irq(void);
extern bool pm_get_wakeup_count(unsigned int *count, bool block);
extern bool pm_save_wakeup_count(unsigned int count);
extern void pm_wakep_autosleep_enabled(bool set);