[3.16.y-ckt stable] Patch "ACPICA: Tables: Don't release ACPI_MTX_TABLES in acpi_tb_install_standard_table()." 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: Don't release ACPI_MTX_TABLES in acpi_tb_install_standard_table().

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-ckt11.

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 0db97c6baaaa846a337702fc3a23b12b05aef754 Mon Sep 17 00:00:00 2001
From: Octavian Purdila <octavian.purdila at intel.com>
Date: Mon, 13 Apr 2015 11:49:05 +0800
Subject: ACPICA: Tables: Don't release ACPI_MTX_TABLES in
 acpi_tb_install_standard_table().

commit 77ddc2fe08329e375505bc36a3df3233fe57317b upstream.

ACPICA commit c70434d4da13e65b6163c79a5aa16b40193631c7

ACPI_MTX_TABLES is acquired and released by the callers of
acpi_tb_install_standard_table() so releasing it in the function itself is
causing the following error in Linux kernel if the table is reloaded:

ACPI Error: Mutex [0x2] is not acquired, cannot release (20141107/utmutex-321)
Call Trace:
  [<ffffffff81b0bd48>] dump_stack+0x4f/0x7b
  [<ffffffff81546bf5>] acpi_ut_release_mutex+0x47/0x67
  [<ffffffff81544357>] acpi_load_table+0x73/0xcb

Link: https://github.com/acpica/acpica/commit/c70434d4
Signed-off-by: Octavian Purdila <octavian.purdila at intel.com>
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/tbinstal.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/acpi/acpica/tbinstal.c b/drivers/acpi/acpica/tbinstal.c
index 755b90c40ddf..c0b39f304ea3 100644
--- a/drivers/acpi/acpica/tbinstal.c
+++ b/drivers/acpi/acpica/tbinstal.c
@@ -346,7 +346,6 @@ acpi_tb_install_standard_table(acpi_physical_address address,
 				 */
 				acpi_tb_uninstall_table(&new_table_desc);
 				*table_index = i;
-				(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 				return_ACPI_STATUS(AE_OK);
 			}
 		}