Merge tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:

 1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction
    of Intel Thunderbolt support on systems that use ACPI for signalling
    Thunderbolt hotplug events.  This also should make ACPIPHP work in
    some cases in which it was known to have problems.  From
    Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov.

 2) ACPI core code cleanups and dock station support cleanups from
    Jiang Liu and Rafael J Wysocki.

 3) Fixes for locking problems related to ACPI device hotplug from
    Rafael J Wysocki.

 4) ACPICA update to version 20130725 includig fixes, cleanups, support
    for more than 256 GPEs per GPE block and a change to make the ACPI
    PM Timer optional (we've seen systems without the PM Timer in the
    field already).  One of the fixes, related to the DeRefOf operator,
    is necessary to prevent some Windows 8 oriented AML from causing
    problems to happen.  From Bob Moore, Lv Zheng, and Jung-uk Kim.

 5) Removal of the old and long deprecated /proc/acpi/event interface
    and related driver changes from Thomas Renninger.

 6) ACPI and Xen changes to make the reduced hardware sleep work with
    the latter from Ben Guthro.

 7) ACPI video driver cleanups and a blacklist of systems that should
    not tell the BIOS that they are compatible with Windows 8 (or ACPI
    backlight and possibly other things will not work on them).  From
    Felipe Contreras.

 8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo,
    Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen,
    Toshi Kani, and Wei Yongjun.

 9) cpufreq ondemand governor target frequency selection change to
    reduce oscillations between min and max frequencies (essentially,
    it causes the governor to choose target frequencies proportional
    to load) from Stratos Karafotis.

10) cpufreq fixes allowing sysfs attributes file permissions to be
    preserved over suspend/resume cycles Srivatsa S Bhat.

11) Removal of Device Tree parsing for CPU device nodes from multiple
    cpufreq drivers that required some changes related to
    of_get_cpu_node() to be made in a few architectures and in the
    driver core.  From Sudeep KarkadaNagesha.

12) cpufreq core fixes and cleanups related to mutual exclusion and
    driver module references from Viresh Kumar, Lukasz Majewski and
    Rafael J Wysocki.

13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap,
    Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo,
    Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd,
    Stratos Karafotis, and Viresh Kumar.

14) Fixes to prevent race conditions in coupled cpuidle from happening
    from Colin Cross.

15) cpuidle core fixes and cleanups from Daniel Lezcano and
    Tuukka Tikkanen.

16) Assorted cpuidle fixes and cleanups from Daniel Lezcano,
    Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij,
    and Sahara.

17) System sleep tracing changes from Todd E Brandt and Shuah Khan.

18) PNP subsystem conversion to using struct dev_pm_ops for power
    management from Shuah Khan.

* tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (217 commits)
  cpufreq: Don't use smp_processor_id() in preemptible context
  cpuidle: coupled: fix race condition between pokes and safe state
  cpuidle: coupled: abort idle if pokes are pending
  cpuidle: coupled: disable interrupts after entering safe state
  ACPI / hotplug: Remove containers synchronously
  driver core / ACPI: Avoid device hot remove locking issues
  cpufreq: governor: Fix typos in comments
  cpufreq: governors: Remove duplicate check of target freq in supported range
  cpufreq: Fix timer/workqueue corruption due to double queueing
  ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT
  ACPI / thermal: Add check of "_TZD" availability and evaluating result
  cpufreq: imx6q: Fix clock enable balance
  ACPI: blacklist win8 OSI for buggy laptops
  cpufreq: tegra: fix the wrong clock name
  cpuidle: Change struct menu_device field types
  cpuidle: Add a comment warning about possible overflow
  cpuidle: Fix variable domains in get_typical_interval()
  cpuidle: Fix menu_device->intervals type
  cpuidle: CodingStyle: Break up multiple assignments on single line
  cpuidle: Check called function parameter in get_typical_interval()
  ...

21 files changed, 241 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/hwesleep.c b/drivers/acpi/acpica/hwesleep.c
index 5e5f76230f5e..414076818d40 100644
--- a/drivers/acpi/acpica/hwesleep.c
+++ b/drivers/acpi/acpica/hwesleep.c
@@ -43,6 +43,7 @@
  */
 
 #include <acpi/acpi.h>
+#include <linux/acpi.h>
 #include "accommon.h"
 
 #define _COMPONENT          ACPI_HARDWARE
@@ -128,6 +129,14 @@ acpi_status acpi_hw_extended_sleep(u8 sleep_state)
 
 	ACPI_FLUSH_CPU_CACHE();
 
+	status = acpi_os_prepare_extended_sleep(sleep_state,
+						acpi_gbl_sleep_type_a,
+						acpi_gbl_sleep_type_b);
+	if (ACPI_SKIP(status))
+		return_ACPI_STATUS(AE_OK);
+	if (ACPI_FAILURE(status))
+		return_ACPI_STATUS(status);
+
 	/*
 	 * Set the SLP_TYP and SLP_EN bits.
 	 *
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,