[PATCH] ACPI: EC: s2idle: Avoid premature returns from acpi_s2idle_wake()

From: Rafael J. Wysocki
Date: Fri May 08 2020 - 12:46:23 EST


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

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 valid subsequent
wakeup events to be missed.

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.

Fixes: d5406284ff80 ("ACPI: PM: s2idle: Refine active GPEs check")
Reported-by: Chris Chiu <chiu@xxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/ec.c | 24 ++++++++++++++++--------
drivers/acpi/internal.h | 1 -
drivers/acpi/sleep.c | 14 ++------------
3 files changed, 18 insertions(+), 21 deletions(-)

Index: linux-pm/drivers/acpi/sleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/sleep.c
+++ linux-pm/drivers/acpi/sleep.c
@@ -1013,21 +1013,11 @@ 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.
*
Index: linux-pm/drivers/acpi/ec.c
===================================================================
--- linux-pm.orig/drivers/acpi/ec.c
+++ linux-pm/drivers/acpi/ec.c
@@ -1994,23 +1994,31 @@ 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 */
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -202,7 +202,6 @@ void acpi_ec_remove_query_handler(struct

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