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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Furquan Shaikh <furquan@google.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 085/271] ACPICA: Clear status of GPEs on first direct enable
Date:   Wed, 24 Jul 2019 21:19:14 +0200
Message-Id: <20190724191702.469790760@linuxfoundation.org>
In-Reply-To: <20190724191655.268628197@linuxfoundation.org>
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[ Upstream commit 44758bafa53602f2581a6857bb20b55d4d8ad5b2 ]

ACPI GPEs (other than the EC one) can be enabled in two situations.
First, the GPEs with existing _Lxx and _Exx methods are enabled
implicitly by ACPICA during system initialization.  Second, the
GPEs without these methods (like GPEs listed by _PRW objects for
wakeup devices) need to be enabled directly by the code that is
going to use them (e.g. ACPI power management or device drivers).

In the former case, if the status of a given GPE is set to start
with, its handler method (either _Lxx or _Exx) needs to be invoked
to take care of the events (possibly) signaled before the GPE was
enabled.  In the latter case, however, the first caller of
acpi_enable_gpe() for a given GPE should not be expected to care
about any events that might be signaled through it earlier.  In
that case, it is better to clear the status of the GPE before
enabling it, to prevent stale events from triggering unwanted
actions (like spurious system resume, for example).

For this reason, modify acpi_ev_add_gpe_reference() to take an
additional boolean argument indicating whether or not the GPE
status needs to be cleared when its reference counter changes from
zero to one and make acpi_enable_gpe() pass TRUE to it through
that new argument.

Fixes: 18996f2db918 ("ACPICA: Events: Stop unconditionally clearing ACPI IRQs during suspend/resume")
Reported-by: Furquan Shaikh <furquan@google.com>
Tested-by: Furquan Shaikh <furquan@google.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/acpica/acevents.h | 3 ++-
 drivers/acpi/acpica/evgpe.c    | 8 +++++++-
 drivers/acpi/acpica/evgpeblk.c | 2 +-
 drivers/acpi/acpica/evxface.c  | 2 +-
 drivers/acpi/acpica/evxfgpe.c  | 2 +-
 5 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h
index 704bebbd35b0..298180bf7e3c 100644
--- a/drivers/acpi/acpica/acevents.h
+++ b/drivers/acpi/acpica/acevents.h
@@ -69,7 +69,8 @@ acpi_status
 acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked);
 
 acpi_status
-acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info);
+acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info,
+			  u8 clear_on_enable);
 
 acpi_status
 acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info);
diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index e10fec99a182..4b5d3b4c627a 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -146,6 +146,7 @@ acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked)
  * FUNCTION:    acpi_ev_add_gpe_reference
  *
  * PARAMETERS:  gpe_event_info          - Add a reference to this GPE
+ *              clear_on_enable         - Clear GPE status before enabling it
  *
  * RETURN:      Status
  *
@@ -155,7 +156,8 @@ acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked)
  ******************************************************************************/
 
 acpi_status
-acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
+acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info,
+			  u8 clear_on_enable)
 {
 	acpi_status status = AE_OK;
 
@@ -170,6 +172,10 @@ acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 
 		/* Enable on first reference */
 
+		if (clear_on_enable) {
+			(void)acpi_hw_clear_gpe(gpe_event_info);
+		}
+
 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 		if (ACPI_SUCCESS(status)) {
 			status = acpi_ev_enable_gpe(gpe_event_info);
diff --git a/drivers/acpi/acpica/evgpeblk.c b/drivers/acpi/acpica/evgpeblk.c
index b253063b09d3..8d96270ed8c7 100644
--- a/drivers/acpi/acpica/evgpeblk.c
+++ b/drivers/acpi/acpica/evgpeblk.c
@@ -453,7 +453,7 @@ acpi_ev_initialize_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
 				continue;
 			}
 
-			status = acpi_ev_add_gpe_reference(gpe_event_info);
+			status = acpi_ev_add_gpe_reference(gpe_event_info, FALSE);
 			if (ACPI_FAILURE(status)) {
 				ACPI_EXCEPTION((AE_INFO, status,
 					"Could not enable GPE 0x%02X",
diff --git a/drivers/acpi/acpica/evxface.c b/drivers/acpi/acpica/evxface.c
index febc332b00ac..841557bda641 100644
--- a/drivers/acpi/acpica/evxface.c
+++ b/drivers/acpi/acpica/evxface.c
@@ -971,7 +971,7 @@ acpi_remove_gpe_handler(acpi_handle gpe_device,
 	      ACPI_GPE_DISPATCH_METHOD) ||
 	     (ACPI_GPE_DISPATCH_TYPE(handler->original_flags) ==
 	      ACPI_GPE_DISPATCH_NOTIFY)) && handler->originally_enabled) {
-		(void)acpi_ev_add_gpe_reference(gpe_event_info);
+		(void)acpi_ev_add_gpe_reference(gpe_event_info, FALSE);
 		if (ACPI_GPE_IS_POLLING_NEEDED(gpe_event_info)) {
 
 			/* Poll edge triggered GPEs to handle existing events */
diff --git a/drivers/acpi/acpica/evxfgpe.c b/drivers/acpi/acpica/evxfgpe.c
index b2d5f66cc1b0..4188731e7c40 100644
--- a/drivers/acpi/acpica/evxfgpe.c
+++ b/drivers/acpi/acpica/evxfgpe.c
@@ -108,7 +108,7 @@ acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number)
 	if (gpe_event_info) {
 		if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) !=
 		    ACPI_GPE_DISPATCH_NONE) {
-			status = acpi_ev_add_gpe_reference(gpe_event_info);
+			status = acpi_ev_add_gpe_reference(gpe_event_info, TRUE);
 			if (ACPI_SUCCESS(status) &&
 			    ACPI_GPE_IS_POLLING_NEEDED(gpe_event_info)) {
 
-- 
2.20.1