Merge remote-tracking branch 'linux-pm/linux-next' into sound/upstream-20250502

Author: bardliao

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -111,6 +111,7 @@ What:		/sys/devices/system/cpu/cpuidle/available_governors
 		/sys/devices/system/cpu/cpuidle/current_driver
 		/sys/devices/system/cpu/cpuidle/current_governor
 		/sys/devices/system/cpu/cpuidle/current_governer_ro
+		/sys/devices/system/cpu/cpuidle/intel_c1_demotion
 Date:		September 2007
 Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
 Description:	Discover cpuidle policy and mechanism
@@ -132,7 +133,11 @@ Description:	Discover cpuidle policy and mechanism
 
 		current_governor_ro: (RO) displays current idle policy.
 
-		See Documentation/admin-guide/pm/cpuidle.rst and
+		intel_c1_demotion: (RW) enables/disables the C1 demotion
+		feature on Intel CPUs.
+
+		See Documentation/admin-guide/pm/cpuidle.rst,
+		Documentation/admin-guide/pm/intel_idle.rst, and
 		Documentation/driver-api/pm/cpuidle.rst for more information.
 
 

Documentation/admin-guide/pm/intel_idle.rst

@@ -38,6 +38,27 @@ instruction at all.
 only way to pass early-configuration-time parameters to it is via the kernel
 command line.
 
+Sysfs Interface
+===============
+
+The ``intel_idle`` driver exposes the following ``sysfs`` attributes in
+``/sys/devices/system/cpu/cpuidle/``:
+
+``intel_c1_demotion``
+	Enable or disable C1 demotion for all CPUs in the system. This file is
+	only exposed on platforms that support the C1 demotion feature and where
+	it was tested. Value 0 means that C1 demotion is disabled, value 1 means
+	that it is enabled. Write 0 or 1 to disable or enable C1 demotion for
+	all CPUs.
+
+	The C1 demotion feature involves the platform firmware demoting deep
+	C-state requests from the OS (e.g., C6 requests) to C1. The idea is that
+	firmware monitors CPU wake-up rate, and if it is higher than a
+	platform-specific threshold, the firmware demotes deep C-state requests
+	to C1. For example, Linux requests C6, but firmware noticed too many
+	wake-ups per second, and it keeps the CPU in C1. When the CPU stays in
+	C1 long enough, the platform promotes it back to C6. This may improve
+	some workloads' performance, but it may also increase power consumption.
 
 .. _intel-idle-enumeration-of-states:
 

Documentation/firmware-guide/acpi/dsd/data-node-references.rst

@@ -12,11 +12,14 @@ ACPI in general allows referring to device objects in the tree only.
 Hierarchical data extension nodes may not be referred to directly, hence this
 document defines a scheme to implement such references.
 
-A reference consist of the device object name followed by one or more
-hierarchical data extension [dsd-guide] keys. Specifically, the hierarchical
-data extension node which is referred to by the key shall lie directly under
-the parent object i.e. either the device object or another hierarchical data
-extension node.
+A reference to a _DSD hierarchical data node is a string consisting of a
+device object reference followed by a dot (".") and a relative path to a data
+node object. Do not use non-string references as this will produce a copy of
+the hierarchical data node, not a reference!
+
+The hierarchical data extension node which is referred to shall be located
+directly under its parent object i.e. either the device object or another
+hierarchical data extension node [dsd-guide].
 
 The keys in the hierarchical data nodes shall consist of the name of the node,
 "@" character and the number of the node in hexadecimal notation (without pre-
@@ -33,11 +36,9 @@ extension key.
 Example
 =======
 
-In the ASL snippet below, the "reference" _DSD property contains a
-device object reference to DEV0 and under that device object, a
-hierarchical data extension key "node@1" referring to the NOD1 object
-and lastly, a hierarchical data extension key "anothernode" referring to
-the ANOD object which is also the final target node of the reference.
+In the ASL snippet below, the "reference" _DSD property contains a string
+reference to a hierarchical data extension node ANOD under DEV0 under the parent
+of DEV1. ANOD is also the final target node of the reference.
 ::
 
 	Device (DEV0)
@@ -76,10 +77,7 @@ the ANOD object which is also the final target node of the reference.
 	    Name (_DSD, Package () {
 		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
 		Package () {
-		    Package () {
-			"reference", Package () {
-			    ^DEV0, "node@1", "anothernode"
-			}
+		    Package () { "reference", "^DEV0.ANOD" }
 		    },
 		}
 	    })

Documentation/firmware-guide/acpi/dsd/graph.rst

@@ -66,12 +66,9 @@ of that port shall be zero. Similarly, if a port may only have a single
 endpoint, the number of that endpoint shall be zero.
 
 The endpoint reference uses property extension with "remote-endpoint" property
-name followed by a reference in the same package. Such references consist of
-the remote device reference, the first package entry of the port data extension
-reference under the device and finally the first package entry of the endpoint
-data extension reference under the port. Individual references thus appear as::
+name followed by a string reference in the same package. [data-node-ref]::
 
-    Package() { device, "port@X", "endpoint@Y" }
+    "device.datanode"
 
 In the above example, "X" is the number of the port and "Y" is the number of
 the endpoint.
@@ -109,7 +106,7 @@ A simple example of this is show below::
 		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
 		Package () {
 		    Package () { "reg", 0 },
-		    Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, "port@4", "endpoint@0" } },
+		    Package () { "remote-endpoint", "\\_SB.PCI0.ISP.EP40" },
 		}
 	    })
 	}
@@ -141,7 +138,7 @@ A simple example of this is show below::
 		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
 		Package () {
 		    Package () { "reg", 0 },
-		    Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, "port@0", "endpoint@0" } },
+		    Package () { "remote-endpoint", "\\_SB.PCI0.I2C2.CAM0.EP00" },
 		}
 	    })
 	}

Documentation/firmware-guide/acpi/dsd/leds.rst

@@ -15,11 +15,6 @@ Referring to LEDs in Device tree is documented in [video-interfaces], in
 "flash-leds" property documentation. In short, LEDs are directly referred to by
 using phandles.
 
-While Device tree allows referring to any node in the tree [devicetree], in
-ACPI references are limited to device nodes only [acpi]. For this reason using
-the same mechanism on ACPI is not possible. A mechanism to refer to non-device
-ACPI nodes is documented in [data-node-ref].
-
 ACPI allows (as does DT) using integer arguments after the reference. A
 combination of the LED driver device reference and an integer argument,
 referring to the "reg" property of the relevant LED, is used to identify
@@ -74,7 +69,7 @@ omitted. ::
 			Package () {
 				Package () {
 					"flash-leds",
-					Package () { ^LED, "led@0", ^LED, "led@1" },
+					Package () { "^LED.LED0", "^LED.LED1" },
 				}
 			}
 		})

drivers/acpi/acpica/acapps.h

@@ -3,7 +3,7 @@
  *
  * Module Name: acapps - common include for ACPI applications/tools
  *
- * Copyright (C) 2000 - 2023, Intel Corp.
+ * Copyright (C) 2000 - 2025, Intel Corp.
  *
  *****************************************************************************/
 
@@ -17,7 +17,7 @@
 /* Common info for tool signons */
 
 #define ACPICA_NAME                 "Intel ACPI Component Architecture"
-#define ACPICA_COPYRIGHT            "Copyright (c) 2000 - 2022 Intel Corporation"
+#define ACPICA_COPYRIGHT            "Copyright (c) 2000 - 2025 Intel Corporation"
 
 #if ACPI_MACHINE_WIDTH == 64
 #define ACPI_WIDTH          " (64-bit version)"

drivers/acpi/acpica/accommon.h

@@ -3,7 +3,7 @@
  *
  * Name: accommon.h - Common include files for generation of ACPICA source
  *
- * Copyright (C) 2000 - 2023, Intel Corp.
+ * Copyright (C) 2000 - 2025, Intel Corp.
  *
  *****************************************************************************/
 

drivers/acpi/acpica/acconvert.h

@@ -3,7 +3,7 @@
  *
  * Module Name: acapps - common include for ACPI applications/tools
  *
- * Copyright (C) 2000 - 2023, Intel Corp.
+ * Copyright (C) 2000 - 2025, Intel Corp.
  *
  *****************************************************************************/
 

drivers/acpi/acpica/acdebug.h

@@ -3,7 +3,7 @@
  *
  * Name: acdebug.h - ACPI/AML debugger
  *
- * Copyright (C) 2000 - 2023, Intel Corp.
+ * Copyright (C) 2000 - 2025, Intel Corp.
  *
  *****************************************************************************/
 
@@ -37,7 +37,7 @@ struct acpi_db_argument_info {
 struct acpi_db_execute_walk {
 	u32 count;
 	u32 max_count;
-	char name_seg[ACPI_NAMESEG_SIZE + 1];
+	char name_seg[ACPI_NAMESEG_SIZE + 1] ACPI_NONSTRING;
 };
 
 #define PARAM_LIST(pl)                  pl

drivers/acpi/acpica/acdispat.h

@@ -3,7 +3,7 @@
  *
  * Name: acdispat.h - dispatcher (parser to interpreter interface)
  *
- * Copyright (C) 2000 - 2023, Intel Corp.
+ * Copyright (C) 2000 - 2025, Intel Corp.
  *
  *****************************************************************************/