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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-02-04 18:35:22 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-02-07 21:02:31 +0100 |
| commit | cb1f65c1e1424a4b5e4a86da8aa3b8fd8459c8ec (patch) | |
| tree | 24fb6cf5301f57a5346c375ae5f5b3cbcc0304ee /kernel/power | |
| parent | dc0075ba7f387fe4c48a8c674b11ab6f374a6acc (diff) | |
| download | linux-cb1f65c1e1424a4b5e4a86da8aa3b8fd8459c8ec.tar.bz2 | |
PM: s2idle: ACPI: Fix wakeup interrupts handling
After commit e3728b50cd9b ("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: e3728b50cd9b ("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>
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/main.c | 5 | ||||
| -rw-r--r-- | kernel/power/process.c | 2 | ||||
| -rw-r--r-- | kernel/power/suspend.c | 2 |
3 files changed, 5 insertions, 4 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c index 44169f3081fd..7e646079fbeb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -504,7 +504,10 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA; + if (!pm_wakeup_irq()) + return -ENODATA; + + return sprintf(buf, "%u\n", pm_wakeup_irq()); } power_attr_ro(pm_wakeup_irq); diff --git a/kernel/power/process.c b/kernel/power/process.c index b7e7798637b8..11b570fcf049 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -134,7 +134,7 @@ int freeze_processes(void) if (!pm_freezing) atomic_inc(&system_freezing_cnt); - pm_wakeup_clear(true); + pm_wakeup_clear(0); pr_info("Freezing user space processes ... "); pm_freezing = true; error = try_to_freeze_tasks(true); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 80cc1f0f502b..6fcdee7e87a5 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -136,8 +136,6 @@ static void s2idle_loop(void) break; } - pm_wakeup_clear(false); - s2idle_enter(); } |