Merge branch 'acpica'

* acpica:
  ACPICA: Update version to 20130725.
  ACPICA: Update names for walk_namespace callbacks to clarify usage.
  ACPICA: Return error if DerefOf resolves to a null package element.
  ACPICA: Make ACPI Power Management Timer (PM Timer) optional.
  ACPICA: Fix divergences of the commit - ACPICA: Expose OSI version.
  ACPICA: Fix possible fault for methods that optionally have no return value.
  ACPICA: DeRefOf operator: Update to fully resolve FieldUnit and BufferField refs.
  ACPICA: Emit all unresolved method externals in a text block
  ACPICA: Export acpi_tb_validate_rsdp().
  ACPI: Add facility to remove all _OSI strings
  ACPI: Add facility to disable all _OSI OS vendor strings
  ACPICA: Add acpi_update_interfaces() public interface
  ACPICA: Update version to 20130626
  ACPICA: Fix compiler warnings for casting issues (only some compilers)
  ACPICA: Remove restriction of 256 maximum GPEs in any GPE block
  ACPICA: Disassembler: Expand maximum output string length to 64K
  ACPICA: TableManager: Export acpi_tb_scan_memory_for_rsdp()
  ACPICA: Update comments about behavior when _STA does not exist

20 files changed, 232 insertions, 77 deletions

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index b8d38117a20c..90e846f985fa 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -138,6 +138,12 @@ u8 ACPI_INIT_GLOBAL(acpi_gbl_disable_auto_repair, FALSE);
  */
 u8 ACPI_INIT_GLOBAL(acpi_gbl_disable_ssdt_table_load, FALSE);
 
+/*
+ * We keep track of the latest version of Windows that has been requested by
+ * the BIOS.
+ */
+u8 ACPI_INIT_GLOBAL(acpi_gbl_osi_data, 0);
+
 /* acpi_gbl_FADT is a local copy of the FADT, converted to a common format. */
 
 struct acpi_table_fadt acpi_gbl_FADT;
@@ -285,7 +291,6 @@ ACPI_EXTERN u8 acpi_gbl_debugger_configuration;
 ACPI_EXTERN u8 acpi_gbl_step_to_next_call;
 ACPI_EXTERN u8 acpi_gbl_acpi_hardware_present;
 ACPI_EXTERN u8 acpi_gbl_events_initialized;
-ACPI_EXTERN u8 acpi_gbl_osi_data;
 ACPI_EXTERN struct acpi_interface_info *acpi_gbl_supported_interfaces;
 ACPI_EXTERN struct acpi_address_range
     *acpi_gbl_address_range_list[ACPI_ADDRESS_RANGE_MAX];
diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index d4a4901637cd..0ed00669cd21 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -942,6 +942,9 @@ struct acpi_interface_info {
 
 #define ACPI_OSI_INVALID                0x01
 #define ACPI_OSI_DYNAMIC                0x02
+#define ACPI_OSI_FEATURE                0x04
+#define ACPI_OSI_DEFAULT_INVALID        0x08
+#define ACPI_OSI_OPTIONAL_FEATURE       (ACPI_OSI_FEATURE | ACPI_OSI_DEFAULT_INVALID | ACPI_OSI_INVALID)
 
 struct acpi_port_info {
         char *name;
@@ -1030,6 +1033,7 @@ struct acpi_external_list {
         u8 type;
         u8 flags;
         u8 resolved;
+        u8 emitted;
 };
 
 /* Values for Flags field above */
diff --git a/drivers/acpi/acpica/acnamesp.h b/drivers/acpi/acpica/acnamesp.h
index b83dc32a5ae0..40b04bd5579e 100644
--- a/drivers/acpi/acpica/acnamesp.h
+++ b/drivers/acpi/acpica/acnamesp.h
@@ -104,8 +104,8 @@ acpi_ns_walk_namespace(acpi_object_type type,
                        acpi_handle start_object,
                        u32 max_depth,
                        u32 flags,
-                       acpi_walk_callback pre_order_visit,
-                       acpi_walk_callback post_order_visit,
+                       acpi_walk_callback descending_callback,
+                       acpi_walk_callback ascending_callback,
                        void *context, void **return_value);
 
 struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
diff --git a/drivers/acpi/acpica/actables.h b/drivers/acpi/acpica/actables.h
index 7755e915a007..c54f42c64fe2 100644
--- a/drivers/acpi/acpica/actables.h
+++ b/drivers/acpi/acpica/actables.h
@@ -47,6 +47,13 @@
 acpi_status acpi_allocate_root_table(u32 initial_table_count);
 
 /*
+ * tbxfroot - Root pointer utilities
+ */
+acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
+
+u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length);
+
+/*
  * tbfadt - FADT parse/convert/validate
  */
 void acpi_tb_parse_fadt(u32 table_index);
diff --git a/drivers/acpi/acpica/acutils.h b/drivers/acpi/acpica/acutils.h
index 3c76edea6803..d5a62a6182bb 100644
--- a/drivers/acpi/acpica/acutils.h
+++ b/drivers/acpi/acpica/acutils.h
@@ -470,6 +470,8 @@ acpi_status acpi_ut_install_interface(acpi_string interface_name);
 
 acpi_status acpi_ut_remove_interface(acpi_string interface_name);
 
+acpi_status acpi_ut_update_interfaces(u8 action);
+
 struct acpi_interface_info *acpi_ut_get_interface(acpi_string interface_name);
 
 acpi_status acpi_ut_osi_implementation(struct acpi_walk_state *walk_state);
@@ -616,7 +618,7 @@ int acpi_ut_stricmp(char *string1, char *string2);
 
 acpi_status acpi_ut_strtoul64(char *string, u32 base, u64 *ret_integer);
 
-void acpi_ut_print_string(char *string, u8 max_length);
+void acpi_ut_print_string(char *string, u16 max_length);
 
 void ut_convert_backslashes(char *pathname);
 
diff --git a/drivers/acpi/acpica/evgpeinit.c b/drivers/acpi/acpica/evgpeinit.c
index 9037f17c9608..7842700346a4 100644
--- a/drivers/acpi/acpica/evgpeinit.c
+++ b/drivers/acpi/acpica/evgpeinit.c
@@ -125,7 +125,6 @@ acpi_status acpi_ev_gpe_initialize(void)
                 /* GPE block 0 exists (has both length and address > 0) */
 
                 register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);
-
                 gpe_number_max =
                     (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;
 
@@ -204,16 +203,6 @@ acpi_status acpi_ev_gpe_initialize(void)
                 goto cleanup;
         }
 
-        /* Check for Max GPE number out-of-range */
-
-        if (gpe_number_max > ACPI_GPE_MAX) {
-                ACPI_ERROR((AE_INFO,
-                            "Maximum GPE number from FADT is too large: 0x%X",
-                            gpe_number_max));
-                status = AE_BAD_VALUE;
-                goto cleanup;
-        }
-
       cleanup:
         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
         return_ACPI_STATUS(AE_OK);
diff --git a/drivers/acpi/acpica/exdump.c b/drivers/acpi/acpica/exdump.c
index c740f24e3101..4d046faac48c 100644
--- a/drivers/acpi/acpica/exdump.c
+++ b/drivers/acpi/acpica/exdump.c
@@ -338,6 +338,7 @@ acpi_ex_dump_object(union acpi_operand_object *obj_desc,
 {
         u8 *target;
         char *name;
+        const char *reference_name;
         u8 count;
 
         if (!info) {
@@ -426,10 +427,9 @@ acpi_ex_dump_object(union acpi_operand_object *obj_desc,
 
                 case ACPI_EXD_REFERENCE:
 
+                        reference_name = acpi_ut_get_reference_name(obj_desc);
                         acpi_ex_out_string("Class Name",
-                                           ACPI_CAST_PTR(char,
-                                                         acpi_ut_get_reference_name
-                                                         (obj_desc)));
+                                           ACPI_CAST_PTR(char, reference_name));
                         acpi_ex_dump_reference_obj(obj_desc);
                         break;
 
diff --git a/drivers/acpi/acpica/exoparg1.c b/drivers/acpi/acpica/exoparg1.c
index 814b4a3d656a..2cdd41d8ade6 100644
--- a/drivers/acpi/acpica/exoparg1.c
+++ b/drivers/acpi/acpica/exoparg1.c
@@ -962,10 +962,17 @@ acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
                                          */
                                         return_desc =
                                             *(operand[0]->reference.where);
-                                        if (return_desc) {
-                                                acpi_ut_add_reference
-                                                    (return_desc);
+                                        if (!return_desc) {
+                                                /*
+                                                 * Element is NULL, do not allow the dereference.
+                                                 * This provides compatibility with other ACPI
+                                                 * implementations.
+                                                 */
+                                                return_ACPI_STATUS
+                                                    (AE_AML_UNINITIALIZED_ELEMENT);
                                         }
+
+                                        acpi_ut_add_reference(return_desc);
                                         break;
 
                                 default:
@@ -990,11 +997,40 @@ acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
                                                                          acpi_namespace_node
                                                                          *)
                                                                         return_desc);
-                                }
+                                        if (!return_desc) {
+                                                break;
+                                        }
 
-                                /* Add another reference to the object! */
+                                        /*
+                                         * 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:
 
-                                acpi_ut_add_reference(return_desc);
+                                                status =
+                                                    acpi_ex_read_data_from_field
+                                                    (walk_state, return_desc,
+                                                     &temp_desc);
+                                                if (ACPI_FAILURE(status)) {
+                                                        goto cleanup;
+                                                }
+
+                                                return_desc = temp_desc;
+                                                break;
+
+                                        default:
+
+                                                /* Add another reference to the object */
+
+                                                acpi_ut_add_reference
+                                                    (return_desc);
+                                                break;
+                                        }
+                                }
                                 break;
 
                         default:
diff --git a/drivers/acpi/acpica/hwtimer.c b/drivers/acpi/acpica/hwtimer.c
index 0c1a8bbd05d6..2d7d22ebc782 100644
--- a/drivers/acpi/acpica/hwtimer.c
+++ b/drivers/acpi/acpica/hwtimer.c
@@ -100,8 +100,13 @@ acpi_status acpi_get_timer(u32 * ticks)
                 return_ACPI_STATUS(AE_BAD_PARAMETER);
         }
 
-        status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
+        /* ACPI 5.0A: PM Timer is optional */
+
+        if (!acpi_gbl_FADT.xpm_timer_block.address) {
+                return_ACPI_STATUS(AE_SUPPORT);
+        }
 
+        status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
         return_ACPI_STATUS(status);
 }
 
@@ -148,6 +153,12 @@ acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
                 return_ACPI_STATUS(AE_BAD_PARAMETER);
         }
 
+        /* ACPI 5.0A: PM Timer is optional */
+
+        if (!acpi_gbl_FADT.xpm_timer_block.address) {
+                return_ACPI_STATUS(AE_SUPPORT);
+        }
+
         /*
          * Compute Tick Delta:
          * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
diff --git a/drivers/acpi/acpica/nspredef.c b/drivers/acpi/acpica/nspredef.c
index 24b71a01bf93..098e7666cbc9 100644
--- a/drivers/acpi/acpica/nspredef.c
+++ b/drivers/acpi/acpica/nspredef.c
@@ -151,6 +151,15 @@ acpi_ns_check_return_value(struct acpi_namespace_node *node,
         }
 
         /*
+         *
+         * 4) If there is no return value and it is optional, just return
+         * AE_OK (_WAK).
+         */
+        if (!(*return_object_ptr)) {
+                goto exit;
+        }
+
+        /*
          * For returned Package objects, check the type of all sub-objects.
          * Note: Package may have been newly created by call above.
          */
@@ -268,7 +277,12 @@ acpi_ns_check_object_type(struct acpi_evaluate_info *info,
 
         acpi_ut_get_expected_return_types(type_buffer, expected_btypes);
 
-        if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
+        if (!return_object) {
+                ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
+                                      info->node_flags,
+                                      "Expected return object of type %s",
+                                      type_buffer));
+        } else if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
                 ACPI_WARN_PREDEFINED((AE_INFO, info->full_pathname,
                                       info->node_flags,
                                       "Return type mismatch - found %s, expected %s",
diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c
index e70911a9e441..e81f15ef659a 100644
--- a/drivers/acpi/acpica/nswalk.c
+++ b/drivers/acpi/acpica/nswalk.c
@@ -156,9 +156,9 @@ struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
  *              max_depth           - Depth to which search is to reach
  *              flags               - Whether to unlock the NS before invoking
  *                                    the callback routine
- *              pre_order_visit     - Called during tree pre-order visit
+ *              descending_callback - Called during tree descent
  *                                    when an object of "Type" is found
- *              post_order_visit    - Called during tree post-order visit
+ *              ascending_callback  - Called during tree ascent
  *                                    when an object of "Type" is found
  *              context             - Passed to user function(s) above
  *              return_value        - from the user_function if terminated
@@ -185,8 +185,8 @@ acpi_ns_walk_namespace(acpi_object_type type,
                        acpi_handle start_node,
                        u32 max_depth,
                        u32 flags,
-                       acpi_walk_callback pre_order_visit,
-                       acpi_walk_callback post_order_visit,
+                       acpi_walk_callback descending_callback,
+                       acpi_walk_callback ascending_callback,
                        void *context, void **return_value)
 {
         acpi_status status;
@@ -255,22 +255,22 @@ acpi_ns_walk_namespace(acpi_object_type type,
                         }
 
                         /*
-                         * Invoke the user function, either pre-order or post-order
+                         * Invoke the user function, either descending, ascending,
                          * or both.
                          */
                         if (!node_previously_visited) {
-                                if (pre_order_visit) {
+                                if (descending_callback) {
                                         status =
-                                            pre_order_visit(child_node, level,
-                                                            context,
-                                                            return_value);
+                                            descending_callback(child_node,
+                                                                level, context,
+                                                                return_value);
                                 }
                         } else {
-                                if (post_order_visit) {
+                                if (ascending_callback) {
                                         status =
-                                            post_order_visit(child_node, level,
-                                                             context,
-                                                             return_value);
+                                            ascending_callback(child_node,
+                                                               level, context,
+                                                               return_value);
                                 }
                         }
 
diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
index f553cfdb71dd..b38b4b07f86e 100644
--- a/drivers/acpi/acpica/nsxfeval.c
+++ b/drivers/acpi/acpica/nsxfeval.c
@@ -533,9 +533,9 @@ static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
  * PARAMETERS:  type                - acpi_object_type to search for
  *              start_object        - Handle in namespace where search begins
  *              max_depth           - Depth to which search is to reach
- *              pre_order_visit     - Called during tree pre-order visit
+ *              descending_callback - Called during tree descent
  *                                    when an object of "Type" is found
- *              post_order_visit    - Called during tree post-order visit
+ *              ascending_callback  - Called during tree ascent
  *                                    when an object of "Type" is found
  *              context             - Passed to user function(s) above
  *              return_value        - Location where return value of
@@ -563,8 +563,8 @@ acpi_status
 acpi_walk_namespace(acpi_object_type type,
                     acpi_handle start_object,
                     u32 max_depth,
-                    acpi_walk_callback pre_order_visit,
-                    acpi_walk_callback post_order_visit,
+                    acpi_walk_callback descending_callback,
+                    acpi_walk_callback ascending_callback,
                     void *context, void **return_value)
 {
         acpi_status status;
@@ -574,7 +574,7 @@ acpi_walk_namespace(acpi_object_type type,
         /* Parameter validation */
 
         if ((type > ACPI_TYPE_LOCAL_MAX) ||
-            (!max_depth) || (!pre_order_visit && !post_order_visit)) {
+            (!max_depth) || (!descending_callback && !ascending_callback)) {
                 return_ACPI_STATUS(AE_BAD_PARAMETER);
         }
 
@@ -606,9 +606,9 @@ acpi_walk_namespace(acpi_object_type type,
         }
 
         status = acpi_ns_walk_namespace(type, start_object, max_depth,
-                                        ACPI_NS_WALK_UNLOCK, pre_order_visit,
-                                        post_order_visit, context,
-                                        return_value);
+                                        ACPI_NS_WALK_UNLOCK,
+                                        descending_callback, ascending_callback,
+                                        context, return_value);
 
         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 
diff --git a/drivers/acpi/acpica/nsxfname.c b/drivers/acpi/acpica/nsxfname.c
index f3a4d95899f7..83c164434580 100644
--- a/drivers/acpi/acpica/nsxfname.c
+++ b/drivers/acpi/acpica/nsxfname.c
@@ -158,6 +158,7 @@ acpi_get_name(acpi_handle handle, u32 name_type, struct acpi_buffer * buffer)
 {
         acpi_status status;
         struct acpi_namespace_node *node;
+        char *node_name;
 
         /* Parameter validation */
 
@@ -202,7 +203,8 @@ acpi_get_name(acpi_handle handle, u32 name_type, struct acpi_buffer * buffer)
 
         /* Just copy the ACPI name from the Node and zero terminate it */
 
-        ACPI_MOVE_NAME(buffer->pointer, acpi_ut_get_node_name(node));
+        node_name = acpi_ut_get_node_name(node);
+        ACPI_MOVE_NAME(buffer->pointer, node_name);
         ((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
         status = AE_OK;
 
@@ -379,9 +381,14 @@ acpi_get_object_info(acpi_handle handle,
                  * Get extra info for ACPI Device/Processor objects only:
                  * Run the _STA, _ADR and, sx_w, and _sx_d methods.
                  *
-                 * Note: none of these methods are required, so they may or may
+                 * Notes: none of these methods are required, so they may or may
                  * not be present for this device. The Info->Valid bitfield is used
                  * to indicate which methods were found and run successfully.
+                 *
+                 * For _STA, if the method does not exist, then (as per the ACPI
+                 * specification), the returned current_status flags will indicate
+                 * that the device is present/functional/enabled. Otherwise, the
+                 * current_status flags reflect the value returned from _STA.
                  */
 
                 /* Execute the Device._STA method */
diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
index 33b00d22300a..9d99f2189693 100644
--- a/drivers/acpi/acpica/tbfadt.c
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -117,7 +117,7 @@ static struct acpi_fadt_info fadt_info_table[] = {
          ACPI_FADT_OFFSET(pm_timer_block),
          ACPI_FADT_OFFSET(pm_timer_length),
          ACPI_PM_TIMER_WIDTH,
-         ACPI_FADT_REQUIRED},
+         ACPI_FADT_SEPARATE_LENGTH},    /* ACPI 5.0A: Timer is optional */
 
         {"Gpe0Block",
          ACPI_FADT_OFFSET(xgpe0_block),
@@ -574,7 +574,7 @@ static void acpi_tb_validate_fadt(void)
 
                 if (fadt_info_table[i].type & ACPI_FADT_REQUIRED) {
                         /*
-                         * Field is required (Pm1a_event, Pm1a_control, pm_timer).
+                         * Field is required (Pm1a_event, Pm1a_control).
                          * Both the address and length must be non-zero.
                          */
                         if (!address64->address || !length) {
diff --git a/drivers/acpi/acpica/tbxfroot.c b/drivers/acpi/acpica/tbxfroot.c
index 7c2ecfb7c2c3..948c95e80d44 100644
--- a/drivers/acpi/acpica/tbxfroot.c
+++ b/drivers/acpi/acpica/tbxfroot.c
@@ -48,11 +48,6 @@
 #define _COMPONENT          ACPI_TABLES
 ACPI_MODULE_NAME("tbxfroot")
 
-/* Local prototypes */
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
-
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
-
 /*******************************************************************************
  *
  * FUNCTION:    acpi_tb_validate_rsdp
@@ -64,8 +59,7 @@ static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
  * DESCRIPTION: Validate the RSDP (ptr)
  *
  ******************************************************************************/
-
-static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
+acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
 {
 
         /*
@@ -74,7 +68,7 @@ static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
          * Note: Sometimes there exists more than one RSDP in memory; the valid
          * RSDP has a valid checksum, all others have an invalid checksum.
          */
-        if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP,
+        if (ACPI_STRNCMP((char *)rsdp->signature, ACPI_SIG_RSDP,
                          sizeof(ACPI_SIG_RSDP) - 1) != 0) {
 
                 /* Nope, BAD Signature */
@@ -231,7 +225,7 @@ acpi_status acpi_find_root_pointer(acpi_size *table_address)
  * DESCRIPTION: Search a block of memory for the RSDP signature
  *
  ******************************************************************************/
-static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
+u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length)
 {
         acpi_status status;
         u8 *mem_rover;
diff --git a/drivers/acpi/acpica/uteval.c b/drivers/acpi/acpica/uteval.c
index ee83adb97b1e..4fd68971019b 100644
--- a/drivers/acpi/acpica/uteval.c
+++ b/drivers/acpi/acpica/uteval.c
@@ -239,7 +239,8 @@ acpi_ut_evaluate_numeric_object(char *object_name,
  * RETURN:      Status
  *
  * DESCRIPTION: Executes _STA for selected device and stores results in
- *              *Flags.
+ *              *Flags. If _STA does not exist, then the device is assumed
+ *              to be present/functional/enabled (as per the ACPI spec).
  *
  *              NOTE: Internal function, no parameter validation
  *
@@ -257,6 +258,11 @@ acpi_ut_execute_STA(struct acpi_namespace_node *device_node, u32 * flags)
                                          ACPI_BTYPE_INTEGER, &obj_desc);
         if (ACPI_FAILURE(status)) {
                 if (AE_NOT_FOUND == status) {
+                        /*
+                         * if _STA does not exist, then (as per the ACPI specification),
+                         * the returned flags will indicate that the device is present,
+                         * functional, and enabled.
+                         */
                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                           "_STA on %4.4s was not found, assuming device is present\n",
                                           acpi_ut_get_node_name(device_node)));
diff --git a/drivers/acpi/acpica/utglobal.c b/drivers/acpi/acpica/utglobal.c
index f736448a8606..d6f26bf8a062 100644
--- a/drivers/acpi/acpica/utglobal.c
+++ b/drivers/acpi/acpica/utglobal.c
@@ -336,7 +336,6 @@ acpi_status acpi_ut_init_globals(void)
         acpi_gbl_trace_dbg_layer = 0;
         acpi_gbl_debugger_configuration = DEBUGGER_THREADING;
         acpi_gbl_db_output_flags = ACPI_DB_CONSOLE_OUTPUT;
-        acpi_gbl_osi_data = 0;
         acpi_gbl_osi_mutex = NULL;
         acpi_gbl_reg_methods_executed = FALSE;
 
diff --git a/drivers/acpi/acpica/utosi.c b/drivers/acpi/acpica/utosi.c
index 7e807725c636..8856bd37bc76 100644
--- a/drivers/acpi/acpica/utosi.c
+++ b/drivers/acpi/acpica/utosi.c
@@ -77,21 +77,20 @@ static struct acpi_interface_info acpi_default_supported_interfaces[] = {
 
         /* Feature Group Strings */
 
-        {"Extended Address Space Descriptor", NULL, 0, 0}
+        {"Extended Address Space Descriptor", NULL, ACPI_OSI_FEATURE, 0},
 
         /*
          * All "optional" feature group strings (features that are implemented
-         * by the host) should be dynamically added by the host via
-         * acpi_install_interface and should not be manually added here.
-         *
-         * Examples of optional feature group strings:
-         *
-         * "Module Device"
-         * "Processor Device"
-         * "3.0 Thermal Model"
-         * "3.0 _SCP Extensions"
-         * "Processor Aggregator Device"
+         * by the host) should be dynamically modified to VALID by the host via
+         * acpi_install_interface or acpi_update_interfaces. Such optional feature
+         * group strings are set as INVALID by default here.
          */
+
+        {"Module Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
+        {"Processor Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
+        {"3.0 Thermal Model", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
+        {"3.0 _SCP Extensions", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
+        {"Processor Aggregator Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0}
 };
 
 /*******************************************************************************
@@ -158,11 +157,20 @@ acpi_status acpi_ut_interface_terminate(void)
         while (next_interface) {
                 acpi_gbl_supported_interfaces = next_interface->next;
 
-                /* Only interfaces added at runtime can be freed */
-
                 if (next_interface->flags & ACPI_OSI_DYNAMIC) {
+
+                        /* Only interfaces added at runtime can be freed */
+
                         ACPI_FREE(next_interface->name);
                         ACPI_FREE(next_interface);
+                } else {
+                        /* Interface is in static list. Reset it to invalid or valid. */
+
+                        if (next_interface->flags & ACPI_OSI_DEFAULT_INVALID) {
+                                next_interface->flags |= ACPI_OSI_INVALID;
+                        } else {
+                                next_interface->flags &= ~ACPI_OSI_INVALID;
+                        }
                 }
 
                 next_interface = acpi_gbl_supported_interfaces;
@@ -278,6 +286,49 @@ acpi_status acpi_ut_remove_interface(acpi_string interface_name)
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ut_update_interfaces
+ *
+ * PARAMETERS:  action              - Actions to be performed during the
+ *                                    update
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Update _OSI interface strings, disabling or enabling OS vendor
+ *              strings or/and feature group strings.
+ *              Caller MUST hold acpi_gbl_osi_mutex
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_update_interfaces(u8 action)
+{
+        struct acpi_interface_info *next_interface;
+
+        next_interface = acpi_gbl_supported_interfaces;
+        while (next_interface) {
+                if (((next_interface->flags & ACPI_OSI_FEATURE) &&
+                     (action & ACPI_FEATURE_STRINGS)) ||
+                    (!(next_interface->flags & ACPI_OSI_FEATURE) &&
+                     (action & ACPI_VENDOR_STRINGS))) {
+                        if (action & ACPI_DISABLE_INTERFACES) {
+
+                                /* Mark the interfaces as invalid */
+
+                                next_interface->flags |= ACPI_OSI_INVALID;
+                        } else {
+                                /* Mark the interfaces as valid */
+
+                                next_interface->flags &= ~ACPI_OSI_INVALID;
+                        }
+                }
+
+                next_interface = next_interface->next;
+        }
+
+        return (AE_OK);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_ut_get_interface
  *
  * PARAMETERS:  interface_name      - The interface to find
diff --git a/drivers/acpi/acpica/utstring.c b/drivers/acpi/acpica/utstring.c
index c53759b76a3f..cb1e9cc32d5f 100644
--- a/drivers/acpi/acpica/utstring.c
+++ b/drivers/acpi/acpica/utstring.c
@@ -333,7 +333,8 @@ acpi_status acpi_ut_strtoul64(char *string, u32 base, u64 *ret_integer)
  * FUNCTION:    acpi_ut_print_string
  *
  * PARAMETERS:  string          - Null terminated ASCII string
- *              max_length      - Maximum output length
+ *              max_length      - Maximum output length. Used to constrain the
+ *                                length of strings during debug output only.
  *
  * RETURN:      None
  *
@@ -342,7 +343,7 @@ acpi_status acpi_ut_strtoul64(char *string, u32 base, u64 *ret_integer)
  *
  ******************************************************************************/
 
-void acpi_ut_print_string(char *string, u8 max_length)
+void acpi_ut_print_string(char *string, u16 max_length)
 {
         u32 i;
 
diff --git a/drivers/acpi/acpica/utxface.c b/drivers/acpi/acpica/utxface.c
index 6505774f223e..03a211e6e26a 100644
--- a/drivers/acpi/acpica/utxface.c
+++ b/drivers/acpi/acpica/utxface.c
@@ -389,6 +389,34 @@ ACPI_EXPORT_SYMBOL(acpi_install_interface_handler)
 
 /*****************************************************************************
  *
+ * FUNCTION:    acpi_update_interfaces
+ *
+ * PARAMETERS:  action              - Actions to be performed during the
+ *                                    update
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Update _OSI interface strings, disabling or enabling OS vendor
+ *              string or/and feature group strings.
+ *
+ ****************************************************************************/
+acpi_status acpi_update_interfaces(u8 action)
+{
+        acpi_status status;
+
+        status = acpi_os_acquire_mutex(acpi_gbl_osi_mutex, ACPI_WAIT_FOREVER);
+        if (ACPI_FAILURE(status)) {
+                return (status);
+        }
+
+        status = acpi_ut_update_interfaces(action);
+
+        acpi_os_release_mutex(acpi_gbl_osi_mutex);
+        return (status);
+}
+
+/*****************************************************************************
+ *
  * FUNCTION:    acpi_check_address_range
  *
  * PARAMETERS:  space_id            - Address space ID
@@ -402,6 +430,7 @@ ACPI_EXPORT_SYMBOL(acpi_install_interface_handler)
  *              ASL operation region address ranges.
  *
  ****************************************************************************/
+
 u32
 acpi_check_address_range(acpi_adr_space_type space_id,
                          acpi_physical_address address,