linux/kernel/power
Rafael J. Wysocki cb1f65c1e1 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>
2022-02-07 21:02:31 +01:00
..
autosleep.c PM: sleep: fix typos in comments 2021-04-08 19:37:21 +02:00
console.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
energy_model.c PM: EM: Mark inefficiencies in CPUFreq 2021-10-05 16:33:05 +02:00
hibernate.c PM: hibernate: use correct mode for swsusp_close() 2021-11-24 13:45:54 +01:00
Kconfig PM: sleep: remove trailing spaces and tabs 2021-06-11 18:49:09 +02:00
main.c PM: s2idle: ACPI: Fix wakeup interrupts handling 2022-02-07 21:02:31 +01:00
Makefile PM: hibernate: Split off snapshot dev option 2020-05-19 17:48:08 +02:00
power.h PM: hibernate: Allow ACPI hardware signature to be honoured 2021-12-08 16:06:10 +01:00
poweroff.c kernel/power: constify sysrq_key_op 2020-05-15 14:53:20 +02:00
process.c PM: s2idle: ACPI: Fix wakeup interrupts handling 2022-02-07 21:02:31 +01:00
qos.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
snapshot.c PM: hibernate: Remove register_nosave_region_late() 2022-01-25 18:34:08 +01:00
suspend_test.c PM: sleep: check RTC features instead of ops in suspend_test 2021-08-04 20:23:05 +02:00
suspend.c PM: s2idle: ACPI: Fix wakeup interrupts handling 2022-02-07 21:02:31 +01:00
swap.c PM: hibernate: Allow ACPI hardware signature to be honoured 2021-12-08 16:06:10 +01:00
user.c PM: hibernate: Fix snapshot partial write lengths 2021-11-24 13:50:18 +01:00
wakelock.c PM: wakeup: simplify the output logic of pm_show_wakelocks() 2022-01-25 18:27:02 +01:00