[PATCH 5.5 15/80] ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system

From: Greg Kroah-Hartman
Date: Tue Feb 18 2020 - 15:06:09 EST

From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

commit fdde0ff8590b4c1c41b3227f5ac4265fccccb96b upstream.

If the platform triggers a spurious SCI even though the status bit
is not set for any GPE when the system is suspended to idle, it will
be treated as a genuine wakeup, so avoid that by checking if any GPEs
are active at all before returning 'true' from acpi_s2idle_wake().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=206413
Fixes: 56b991849009 ("PM: sleep: Simplify suspend-to-idle control flow")
Reported-by: Tsuchiya Yuto <kitakar@xxxxxxxxx>
Cc: 5.4+ <stable@xxxxxxxxxxxxxxx> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/acpi/sleep.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -1003,10 +1003,16 @@ static bool acpi_s2idle_wake(void)
return true;

- * If there are no EC events to process, the wakeup is regarded
- * as a genuine one.
+ * If there are no EC events to process and at least one of the
+ * other enabled GPEs is active, the wakeup is regarded as a
+ * genuine one.
+ *
+ * Note that the checks below must be carried out in this order
+ * to avoid returning prematurely due to a change of the EC GPE
+ * status bit from unset to set between the checks with the
+ * status bits of all the other GPEs unset.
- if (!acpi_ec_dispatch_gpe())
+ if (acpi_any_gpe_status_set() && !acpi_ec_dispatch_gpe())
return true;