[PATCH 5.6 074/194] ACPI: EC: PM: Avoid premature returns from acpi_s2idle_wake()

Greg Kroah-Hartman
2020-05-18T18:02:53Z

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

[ Upstream commit 7b301750f7f8f6503e11f1af4a03832525f58c66 ]

If the EC GPE status is not set after checking all of the other GPEs,
acpi_s2idle_wake() returns 'false', to indicate that the SCI event
that has just triggered is not a system wakeup one, but it does that
without canceling the pending wakeup and re-arming the SCI for system
wakeup which is a mistake, because it may cause s2idle_loop() to busy
spin until the next valid wakeup event. [If that happens, the first
spurious wakeup is still pending after acpi_s2idle_wake() has
returned, so s2idle_enter() does nothing, acpi_s2idle_wake()
is called again and it sees that the SCI has triggered, but no GPEs
are active, so 'false' is returned again, and so on.]

Fix that by moving all of the GPE checking logic from
acpi_s2idle_wake() to acpi_ec_dispatch_gpe() and making the
latter return 'true' only if a non-EC GPE has triggered and
'false' otherwise, which will cause acpi_s2idle_wake() to
cancel the pending SCI wakeup and re-arm the SCI for system
wakeup regardless of the EC GPE status.

This also addresses a lockup observed on an Elitegroup EF20EA laptop
after attempting to wake it up from suspend-to-idle by a key press.

Fixes: d5406284ff80 ("ACPI: PM: s2idle: Refine active GPEs check")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207603
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Fixes: fdde0ff8590b ("ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system")
Link: https://lore.kernel.org/linux-acpi/CAB4CAwdqo7=MvyG_PE+PGVfeA17AHF5i5JucgaKqqMX6mjArbQ@mail.gmail.com/
Reported-by: Chris Chiu <chiu@endlessm.com>
Tested-by: Chris Chiu <chiu@endlessm.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/acpi/ec.c | 24 ++++++++++++++++--------
drivers/acpi/internal.h | 1 -
drivers/acpi/sleep.c | 14 ++------------
3 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 35dd2f1fb0e61..03b3067811c99 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -2042,23 +2042,31 @@ void acpi_ec_set_gpe_wake_mask(u8 action)
acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
}

-bool acpi_ec_other_gpes_active(void)
-{
- return acpi_any_gpe_status_set(first_ec ? first_ec->gpe : U32_MAX);
-}
-
bool acpi_ec_dispatch_gpe(void)
{
u32 ret;

if (!first_ec)
+ return acpi_any_gpe_status_set(U32_MAX);
+
+ /*
+ * Report wakeup if the status bit is set for any enabled GPE other
+ * than the EC one.
+ */
+ if (acpi_any_gpe_status_set(first_ec->gpe))
+ return true;
+
+ if (ec_no_wakeup)
return false;

+ /*
+ * Dispatch the EC GPE in-band, but do not report wakeup in any case
+ * to allow the caller to process events properly after that.
+ */
ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
- if (ret == ACPI_INTERRUPT_HANDLED) {
+ if (ret == ACPI_INTERRUPT_HANDLED)
pm_pr_dbg("EC GPE dispatched\n");
- return true;
- }
+
return false;
}
#endif /* CONFIG_PM_SLEEP */
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index d44c591c4ee4d..3616daec650b1 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -202,7 +202,6 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);

#ifdef CONFIG_PM_SLEEP
void acpi_ec_flush_work(void);
-bool acpi_ec_other_gpes_active(void);
bool acpi_ec_dispatch_gpe(void);
#endif

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 4edc8a3ce40fd..3850704570c0c 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -1013,20 +1013,10 @@ static bool acpi_s2idle_wake(void)
if (acpi_check_wakeup_handlers())
return true;

- /*
- * If the status bit is set for any enabled GPE other than the
- * EC one, the wakeup is regarded as a genuine one.
- */
- if (acpi_ec_other_gpes_active())
+ /* Check non-EC GPE wakeups and dispatch the EC GPE. */
+ if (acpi_ec_dispatch_gpe())
return true;

- /*
- * If the EC GPE status bit has not been set, the wakeup is
- * regarded as a spurious one.
- */
- if (!acpi_ec_dispatch_gpe())
- return false;
-
/*
* Cancel the wakeup and process all pending events in case
* there are any wakeup ones in there.
--
2.20.1