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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-02-11 10:11:02 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-02-11 10:11:02 +0100 |
| commit | e3728b50cd9be7d4b1469447cdf1feb93e3b7adb (patch) | |
| tree | 446902616310615718c4615e9dbe1a1ea2e5a914 /kernel | |
| parent | f0ac20c3f6137910c8a927953e8a92f5b3716166 (diff) | |
| download | linux-e3728b50cd9be7d4b1469447cdf1feb93e3b7adb.tar.bz2 | |
ACPI: PM: s2idle: Avoid possible race related to the EC GPE
It is theoretically possible for the ACPI EC GPE to be set after the
s2idle_ops->wake() called from s2idle_loop() has returned and before
the subsequent pm_wakeup_pending() check is carried out. If that
happens, the resulting wakeup event will cause the system to resume
even though it may be a spurious one.
To avoid that race, first make the ->wake() callback in struct
platform_s2idle_ops return a bool value indicating whether or not
to let the system resume and rearrange s2idle_loop() to use that
value instad of the direct pm_wakeup_pending() call if ->wake() is
present.
Next, rework acpi_s2idle_wake() to process EC events and check
pm_wakeup_pending() before re-arming the SCI for system wakeup
to prevent it from triggering prematurely and add comments to
that function to explain the rationale for the new code flow.
Fixes: 56b991849009 ("PM: sleep: Simplify suspend-to-idle control flow")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/power/suspend.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 2c47280fbfc7..8b1bb5ee7e5d 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -131,11 +131,12 @@ static void s2idle_loop(void) * to avoid them upfront. */ for (;;) { - if (s2idle_ops && s2idle_ops->wake) - s2idle_ops->wake(); - - if (pm_wakeup_pending()) + if (s2idle_ops && s2idle_ops->wake) { + if (s2idle_ops->wake()) + break; + } else if (pm_wakeup_pending()) { break; + } pm_wakeup_clear(false); |