[3.16.y-ckt stable] Patch "ACPICA: Tables: Fix an issue that FACS initialization is performed twice" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ACPICA: Tables: Fix an issue that FACS initialization is performed twice

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt15.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From d8df81ba4c96645add45bc7ee531373058447441 Mon Sep 17 00:00:00 2001
From: Lv Zheng <lv.zheng at intel.com>
Date: Wed, 1 Jul 2015 14:43:26 +0800
Subject: ACPICA: Tables: Fix an issue that FACS initialization is performed
 twice

commit c04be18448355441a0c424362df65b6422e27bda upstream.

ACPICA commit 90f5332a15e9d9ba83831ca700b2b9f708274658

This patch adds a new FACS initialization flag for acpi_tb_initialize().
acpi_enable_subsystem() might be invoked several times in OS bootup process,
and we don't want FACS initialization to be invoked twice. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/90f5332a
Signed-off-by: Lv Zheng <lv.zheng at intel.com>
Signed-off-by: Bob Moore <robert.moore at intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/acpi/acpica/utxfinit.c | 10 ++++++----
 include/acpi/actypes.h         |  1 +
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/acpica/utxfinit.c b/drivers/acpi/acpica/utxfinit.c
index 13380d818462..64f8f307243b 100644
--- a/drivers/acpi/acpica/utxfinit.c
+++ b/drivers/acpi/acpica/utxfinit.c
@@ -175,10 +175,12 @@ acpi_status __init acpi_enable_subsystem(u32 flags)
 	 * Obtain a permanent mapping for the FACS. This is required for the
 	 * Global Lock and the Firmware Waking Vector
 	 */
-	status = acpi_tb_initialize_facs();
-	if (ACPI_FAILURE(status)) {
-		ACPI_WARNING((AE_INFO, "Could not map the FACS table"));
-		return_ACPI_STATUS(status);
+	if (!(flags & ACPI_NO_FACS_INIT)) {
+		status = acpi_tb_initialize_facs();
+		if (ACPI_FAILURE(status)) {
+			ACPI_WARNING((AE_INFO, "Could not map the FACS table"));
+			return_ACPI_STATUS(status);
+		}
 	}
 #endif				/* !ACPI_REDUCED_HARDWARE */

diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index f0a23d7fd302..00b6e76c8d4c 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -572,6 +572,7 @@ typedef u64 acpi_integer;
 #define ACPI_NO_ACPI_ENABLE             0x10
 #define ACPI_NO_DEVICE_INIT             0x20
 #define ACPI_NO_OBJECT_INIT             0x40
+#define ACPI_NO_FACS_INIT               0x80

 /*
  * Initialization state