[3.5.y.z extended stable] Patch "ACPICA: DeRefOf operator: Update to fully resolve FieldUnit and" 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: DeRefOf operator: Update to fully resolve FieldUnit and

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

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

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From af37bab44dc8df65a89f488991686a6b8f1e3a5c Mon Sep 17 00:00:00 2001
From: Bob Moore <robert.moore at intel.com>
Date: Thu, 8 Aug 2013 15:29:32 +0800
Subject: ACPICA: DeRefOf operator: Update to fully resolve FieldUnit and
 BufferField refs.

commit 63660e05ec719613b518547b40a1c501c10f0bc4 upstream.

Previously, references to these objects were resolved only to the actual
FieldUnit or BufferField object. The correct behavior is to resolve these
references to an actual value.
The problem is that DerefOf did not resolve these objects to actual
values.  An "Integer" object is simple, return the value.  But a field in
an operation region will require a read operation.  For a BufferField, the
appropriate data must be extracted from the parent buffer.

NOTE: It appears that this issues is present in Windows7 but not
Windows8.

Signed-off-by: Bob Moore <robert.moore at intel.com>
Signed-off-by: Lv Zheng <lv.zheng 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/exoparg1.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/acpica/exoparg1.c b/drivers/acpi/acpica/exoparg1.c
index 9ba8c73..fb8772d 100644
--- a/drivers/acpi/acpica/exoparg1.c
+++ b/drivers/acpi/acpica/exoparg1.c
@@ -998,11 +998,40 @@ acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
 									 acpi_namespace_node
 									 *)
 									return_desc);
-				}
+					if (!return_desc) {
+						break;
+					}
+
+					/*
+					 * June 2013:
+					 * buffer_fields/field_units require additional resolution
+					 */
+					switch (return_desc->common.type) {
+					case ACPI_TYPE_BUFFER_FIELD:
+					case ACPI_TYPE_LOCAL_REGION_FIELD:
+					case ACPI_TYPE_LOCAL_BANK_FIELD:
+					case ACPI_TYPE_LOCAL_INDEX_FIELD:
+
+						status =
+						    acpi_ex_read_data_from_field
+						    (walk_state, return_desc,
+						     &temp_desc);
+						if (ACPI_FAILURE(status)) {
+							goto cleanup;
+						}

-				/* Add another reference to the object! */
+						return_desc = temp_desc;
+						break;

-				acpi_ut_add_reference(return_desc);
+					default:
+
+						/* Add another reference to the object */
+
+						acpi_ut_add_reference
+						    (return_desc);
+						break;
+					}
+				}
 				break;

 			default:
--
1.8.3.2