[3.16.y-ckt stable] Patch "ACPICA: Tables: Enable default 64-bit FADT addresses favor" 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: Enable default 64-bit FADT addresses favor

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 d1df8a576b0ee7f6fa63561ba040af9c6912b9b7 Mon Sep 17 00:00:00 2001
From: Lv Zheng <lv.zheng at intel.com>
Date: Wed, 1 Jul 2015 14:43:34 +0800
Subject: ACPICA: Tables: Enable default 64-bit FADT addresses favor

commit 0ea61381788a37d864f9841b0fe97d40f7058f3b upstream.

ACPICA commit 4da56eeae0749dfe8491285c1e1fad48f6efafd8

The following commit temporarily disables correct 64-bit FADT addresses
favor during the period the root cause of the bug is not fixed:
 Commit: 85dbd5801f62b66e2aa7826aaefcaebead44c8a6
 ACPICA: Tables: Restore old behavor to favor 32-bit FADT addresses.

With enough protections, this patch re-enables 64-bit FADT addresses by
default. If regressions are reported against such change, this patch should
be bisected and reverted.
Note that 64-bit FACS favor and 64-bit firmware waking vector favor are
excluded by this commit in order not to break OSPMs. Lv Zheng.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=74021
Link: https://github.com/acpica/acpica/commit/4da56eea
Reported-and-tested-by: Oswald Buddenhagen <ossi at kde.org>
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>
---
 include/acpi/acpixf.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 77391cfd7c6b..d95681144545 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -197,9 +197,9 @@ ACPI_INIT_GLOBAL(u8, acpi_gbl_do_not_use_xsdt, FALSE);
  * address. Although ACPICA adheres to the ACPI specification which
  * requires the use of the corresponding 64-bit address if it is non-zero,
  * some machines have been found to have a corrupted non-zero 64-bit
- * address. Default is TRUE, favor the 32-bit addresses.
+ * address. Default is FALSE, do not favor the 32-bit addresses.
  */
-ACPI_INIT_GLOBAL(u8, acpi_gbl_use32_bit_fadt_addresses, TRUE);
+ACPI_INIT_GLOBAL(u8, acpi_gbl_use32_bit_fadt_addresses, FALSE);

 /*
  * Optionally use 32-bit FACS table addresses.