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

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Date:   Fri, 04 Feb 2022 18:31:02 +0100
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        David Box <david.e.box@...ux.intel.com>
Subject: [PATCH v1 1/2] ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE

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

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@...el.com>
---
 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();
 
 		/*