Linux 4.19.35

[thirdparty/kernel/stable-queue.git] / releases / 4.19.35 / acpica-clear-status-of-gpes-before-enabling-them.patch

From c8b1917c8987a6fa3695d479b4d60fbbbc3e537b Mon Sep 17 00:00:00 2001
From: Furquan Shaikh <furquan@google.com>
Date: Wed, 20 Mar 2019 15:28:44 -0700
Subject: ACPICA: Clear status of GPEs before enabling them

From: Furquan Shaikh <furquan@google.com>

commit c8b1917c8987a6fa3695d479b4d60fbbbc3e537b upstream.

Commit 18996f2db918 ("ACPICA: Events: Stop unconditionally clearing
ACPI IRQs during suspend/resume") was added to stop clearing event
status bits unconditionally in the system-wide suspend and resume
paths. This was done because of an issue with a laptop lid appaering
to be closed even when it was used to wake up the system from suspend
(see https://bugzilla.kernel.org/show_bug.cgi?id=196249), which
happened because event status bits were cleared unconditionally on
system resume. Though this change fixed the issue in the resume path,
it introduced regressions in a few suspend paths.

First regression was reported and fixed in the S5 entry path by commit
fa85015c0d95 ("ACPICA: Clear status of all events when entering S5").
Next regression was reported and fixed for all legacy sleep paths by
commit f317c7dc12b7 ("ACPICA: Clear status of all events when entering
sleep states").  However, there still is a suspend-to-idle regression,
since suspend-to-idle does not follow the legacy sleep paths.

In the suspend-to-idle case, wakeup is enabled as part of device
suspend.  If the status bits of wakeup GPEs are set when they are
enabled, it causes a premature system wakeup to occur.

To address that problem, partially revert commit 18996f2db918 to
restore GPE status bits clearing before the GPE is enabled in
acpi_ev_enable_gpe().

Fixes: 18996f2db918 ("ACPICA: Events: Stop unconditionally clearing ACPI IRQs during suspend/resume")
Signed-off-by: Furquan Shaikh <furquan@google.com>
Cc: 4.17+ <stable@vger.kernel.org> # 4.17+
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/acpi/acpica/evgpe.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -81,8 +81,12 @@ acpi_status acpi_ev_enable_gpe(struct ac
 
 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
 
-	/* Enable the requested GPE */
+	/* Clear the GPE status */
+	status = acpi_hw_clear_gpe(gpe_event_info);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
 
+	/* Enable the requested GPE */
 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
 	return_ACPI_STATUS(status);
 }