[PATCH v1 1/2] ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE

From: Rafael J. Wysocki
Date: Fri Feb 04 2022 - 12:36:07 EST


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

Commit 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while
suspended to idle") made acpi_ec_dispatch_gpe() check
pm_wakeup_pending(), but that is before canceling the SCI wakeup,
so pm_wakeup_pending() is always true. This causes the loop in
acpi_ec_dispatch_gpe() to always terminate after one iteration which
may not be correct.

Address this issue by canceling the SCI wakeup earlier, from
acpi_ec_dispatch_gpe() itself.

Fixes: 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while suspended to idle")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/ec.c | 10 ++++++++++
drivers/acpi/sleep.c | 15 +++++----------
2 files changed, 15 insertions(+), 10 deletions(-)

Index: linux-pm/drivers/acpi/ec.c
===================================================================
--- linux-pm.orig/drivers/acpi/ec.c
+++ linux-pm/drivers/acpi/ec.c
@@ -2066,6 +2066,16 @@ bool acpi_ec_dispatch_gpe(void)
return true;

/*
+ * Cancel the SCI wakeup and process all pending events in case there
+ * are any wakeup ones in there.
+ *
+ * Note that if any non-EC GPEs are active at this point, the SCI will
+ * retrigger after the rearming in acpi_s2idle_wake(), so no events
+ * should be missed by canceling the wakeup here.
+ */
+ pm_system_cancel_wakeup();
+
+ /*
* Dispatch the EC GPE in-band, but do not report wakeup in any case
* to allow the caller to process events properly after that.
*/
Index: linux-pm/drivers/acpi/sleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/sleep.c
+++ linux-pm/drivers/acpi/sleep.c
@@ -736,21 +736,15 @@ bool acpi_s2idle_wake(void)
return true;
}

- /* Check non-EC GPE wakeups and dispatch the EC GPE. */
+ /*
+ * Check non-EC GPE wakeups and if there are none, cancel the
+ * SCI-related wakeup and dispatch the EC GPE.
+ */
if (acpi_ec_dispatch_gpe()) {
pm_pr_dbg("ACPI non-EC GPE wakeup\n");
return true;
}

- /*
- * Cancel the SCI wakeup and process all pending events in case
- * there are any wakeup ones in there.
- *
- * Note that if any non-EC GPEs are active at this point, the
- * SCI will retrigger after the rearming below, so no events
- * should be missed by canceling the wakeup here.
- */
- pm_system_cancel_wakeup();
acpi_os_wait_events_complete();

/*