ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system

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@gmail.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 2c695b1..152f7fc 100644 (file)
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -1006,10 +1006,16 @@ 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;
 
                /*