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-rw-r--r--Documentation/admin-guide/acpi/cppc_sysfs.rst2
-rw-r--r--Documentation/admin-guide/acpi/dsdt-override.rst13
-rw-r--r--Documentation/admin-guide/acpi/fan_performance_states.rst28
-rw-r--r--Documentation/admin-guide/acpi/index.rst1
4 files changed, 30 insertions, 14 deletions
diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst
index fccf22114e85..e53d76365aa7 100644
--- a/Documentation/admin-guide/acpi/cppc_sysfs.rst
+++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst
@@ -4,6 +4,8 @@
Collaborative Processor Performance Control (CPPC)
==================================================
+.. _cppc_sysfs:
+
CPPC
====
diff --git a/Documentation/admin-guide/acpi/dsdt-override.rst b/Documentation/admin-guide/acpi/dsdt-override.rst
deleted file mode 100644
index 50bd7f194bf4..000000000000
--- a/Documentation/admin-guide/acpi/dsdt-override.rst
+++ /dev/null
@@ -1,13 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-===============
-Overriding DSDT
-===============
-
-Linux supports a method of overriding the BIOS DSDT:
-
-CONFIG_ACPI_CUSTOM_DSDT - builds the image into the kernel.
-
-When to use this method is described in detail on the
-Linux/ACPI home page:
-https://01.org/linux-acpi/documentation/overriding-dsdt
diff --git a/Documentation/admin-guide/acpi/fan_performance_states.rst b/Documentation/admin-guide/acpi/fan_performance_states.rst
index 98fe5c333121..b9e4b4d146c1 100644
--- a/Documentation/admin-guide/acpi/fan_performance_states.rst
+++ b/Documentation/admin-guide/acpi/fan_performance_states.rst
@@ -60,3 +60,31 @@ For example::
When a given field is not populated or its value provided by the platform
firmware is invalid, the "not-defined" string is shown instead of the value.
+
+ACPI Fan Fine Grain Control
+=============================
+
+When _FIF object specifies support for fine grain control, then fan speed
+can be set from 0 to 100% with the recommended minimum "step size" via
+_FSL object. User can adjust fan speed using thermal sysfs cooling device.
+
+Here use can look at fan performance states for a reference speed (speed_rpm)
+and set it by changing cooling device cur_state. If the fine grain control
+is supported then user can also adjust to some other speeds which are
+not defined in the performance states.
+
+The support of fine grain control is presented via sysfs attribute
+"fine_grain_control". If fine grain control is present, this attribute
+will show "1" otherwise "0".
+
+This sysfs attribute is presented in the same directory as performance states.
+
+ACPI Fan Performance Feedback
+=============================
+
+The optional _FST object provides status information for the fan device.
+This includes field to provide current fan speed in revolutions per minute
+at which the fan is rotating.
+
+This speed is presented in the sysfs using the attribute "fan_speed_rpm",
+in the same directory as performance states.
diff --git a/Documentation/admin-guide/acpi/index.rst b/Documentation/admin-guide/acpi/index.rst
index 71277689ad97..b078fdb8f4c9 100644
--- a/Documentation/admin-guide/acpi/index.rst
+++ b/Documentation/admin-guide/acpi/index.rst
@@ -9,7 +9,6 @@ the Linux ACPI support.
:maxdepth: 1
initrd_table_override
- dsdt-override
ssdt-overlays
cppc_sysfs
fan_performance_states