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Linus Torvalds a5778046a0 Power management updates for 7.3-rc1
- Minor fixes and cleanups in assorted cpufreq drivers (Dan Carpenter,
    Guru Das Srinagesh, Haoxiang Li, Karl Mehltretter, Sasha Finkelstein,
    and Pan Chuang)
 
  - Fix cpufreq table creation and bios_limits() callback in the Rust
    bindings (Priya Bala Govindasamy)
 
  - Add IPQ5210 support to qcom-nvmem driver (Varadarajan Narayanan)
 
  - Adjust the .adjust_perf() cpufreq driver callback to allow the
    maximum performance value to be passed to drivers and update the
    intel_pstate driver to use it (Rafael Wysocki)
 
  - Set policy->cur to the actual requested frequency in the intel_pstate
    driver when the performance policy is used (Rafael Wysocki)
 
  - Simplify HWP handling on Broadwell processors in intel_pstate (Rafael
    Wysocki)
 
  - Fix setting minimum P-state at init time in intel_pstate (Rafael
    Wysocki)
 
  - Consolidate frequency values computation in intel_pstate and clean up
    code in that driver (Rafael Wysocki)
 
  - Add missing kernel-doc descriptions for structure and union members
    in the amd-pstate driver (David Vernet)
 
  - Handle missing policy in dynamic EPP callbacks in the amd-pstate
    driver (EDAMAMEX)
 
  - Introduce EXPORT_SYMBOL_FOR_PSTATE_UT() to export amd-pstate driver
    symbols to the amd-pstate-ut subdriver (K Prateek Nayak)
 
  - Add dynamic EPP as an "energy_performance_preference" mode in
    amd-pstate, remove the "amd_dynamic_epp" kernel command line option
    and the "dynamic_epp" sysfs attribute, and update the dynamic_epp
    documentation accordingly (K Prateek Nayak)
 
  - Add unit tests for CPPC Performance Priority and the "dynamic" EPP
    mode in the amd-pstate driver (K Prateek Nayak)
 
  - Set min_limit_freq based on bios_min_perf in amd-pstate and remove
    the defensive check for bios_min_perf from it (K Prateek Nayak)
 
  - Fix EPP return type and handle errors in amd-pstate during
    initialization, toggle auto_sel in active mode on shared memory
    systems, and cache the firmware programmed EPP value (Marco Scardovi)
 
  - Skip tests in amd-pstate-ut if the amd-pstate driver is not in active
    use (Qianheng Peng)
 
  - Replace sprintf() with sysfs_emit() in sysfs show in the cpufreq
    schedutil governor and fix a self-contradictory comment in
    sugov_iowait_apply() (Zhongqiu Han)
 
  - Fix the usage example for the sampling_rate tunable of the ondemand
    cpufreq governor in admin-guide (wangxiaodong)
 
  - Avoid using deep idle states during initialization in the intel_idle
    driver to work around device handling issues (Rafael Wysocki)
 
  - Fix and refactor the ACPI processor driver code related to ACPI _LPI
    support and add ACPI _LPI support to intel_idle based on that ACPI
    processor driver update (Rafael Wysocki)
 
  - Backup and restore governor for cpufreq sptests (Yiwei Lin)
 
  - Remove unnecessary sudo from quick_shuffle() and remove unused local
    variables from switch_show_governor() in cpufreq selftests (Jinseok
    Kim)
 
  - Rename the PM core module parameter prefix to "pm" and allow the PM
    transition (DPM) watchdog to be disabled by default (Tzung-Bi Shih)
 
  - Fix off-by-one in wakelocks number limit check in the system sleep
    sysfs interface (Haowen Tu)
 
  - Remove kernel-doc markings from helper descriptions in the core
    hibernation code (Adi Nata)
 
  - Use %pe to print error pointer values in the hibernation core (Ronan
    Marchal)
 
  - Fix memory leak in snapshot_write_next() error path (Malaya Kumar
    Rout)
 
  - Delay allocating and linking the next swap_map_page in the
    hibernation image saving code until another image page actually
    needs to be recorded (Haesung Kim)
 
  - Fix cleanup ordering around scope-based pointers in OPP (Gregor
    Herburger).
 
  - Use clk_get_optional() for optional clocks in OPP (Praveen Talari).
 
  - Stop setting runtime_error on runtime resume callback failures to
    allow drivers to recover from resume issues (Praveen Talari)
 
  - Handle PMU registration failure during probe in the intel_rapl_tpmi
    driver (Sumeet Pawnikar)
 
  - Avoid optional imports in intel_pstate_tracer unless they are really
    needed (Yousef Alhouseen)
 
  - Add generic CPPC performance display to the cpupower utility, build
    and call CPPC information on non-AMD processors, make cpupower print
    kernel and hardware frequency information, and add libm to cpupower
    for generic CPPC view (Jeremy Linton)
 
  - Remove conditional return with no effect from cpupower (Sang-Heon
    Jeon)
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Merge tag 'pm-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "As has been the case for quite some time, this set of changes is
  dominated by cpufreq updates including intel-pstate and amd-pstate
  driver updates, minor fixes and cleanups of other assorted cpufreq
  drivers, schedutil governor updates, fixes of the Rust bindings, new
  hardware support (IPQ5210 in qcom-nvmem), and some updates of self
  tests related to cpufreq.

  The second largest group of changes are cpuidle updates consisting of
  intel_idle driver updates and ACPI processor idle driver updates, both
  mostly related to ACPI _LPI support.

  There are also updates related to system sleep, mostly in the
  hibernation core code, two operating performance points (OPP) updates,
  one runtime PM framework update, one power capping update, and some
  tools updates including the addition of ACPI CPPC support to cpupower.

  Specifics:

   - Minor fixes and cleanups in assorted cpufreq drivers (Dan
     Carpenter, Guru Das Srinagesh, Haoxiang Li, Karl Mehltretter, Sasha
     Finkelstein, and Pan Chuang)

   - Fix cpufreq table creation and bios_limits() callback in the Rust
     bindings (Priya Bala Govindasamy)

   - Add IPQ5210 support to qcom-nvmem driver (Varadarajan Narayanan)

   - Adjust the .adjust_perf() cpufreq driver callback to allow the
     maximum performance value to be passed to drivers and update the
     intel_pstate driver to use it (Rafael Wysocki)

   - Set policy->cur to the actual requested frequency in the
     intel_pstate driver when the performance policy is used (Rafael
     Wysocki)

   - Simplify HWP handling on Broadwell processors in intel_pstate
     (Rafael Wysocki)

   - Fix setting minimum P-state at init time in intel_pstate (Rafael
     Wysocki)

   - Consolidate frequency values computation in intel_pstate and clean
     up code in that driver (Rafael Wysocki)

   - Add missing kernel-doc descriptions for structure and union members
     in the amd-pstate driver (David Vernet)

   - Handle missing policy in dynamic EPP callbacks in the amd-pstate
     driver (EDAMAMEX)

   - Introduce EXPORT_SYMBOL_FOR_PSTATE_UT() to export amd-pstate driver
     symbols to the amd-pstate-ut subdriver (K Prateek Nayak)

   - Add dynamic EPP as an "energy_performance_preference" mode in
     amd-pstate, remove the "amd_dynamic_epp" kernel command line option
     and the "dynamic_epp" sysfs attribute, and update the dynamic_epp
     documentation accordingly (K Prateek Nayak)

   - Add unit tests for CPPC Performance Priority and the "dynamic" EPP
     mode in the amd-pstate driver (K Prateek Nayak)

   - Set min_limit_freq based on bios_min_perf in amd-pstate and remove
     the defensive check for bios_min_perf from it (K Prateek Nayak)

   - Fix EPP return type and handle errors in amd-pstate during
     initialization, toggle auto_sel in active mode on shared memory
     systems, and cache the firmware programmed EPP value (Marco
     Scardovi)

   - Skip tests in amd-pstate-ut if the amd-pstate driver is not in
     active use (Qianheng Peng)

   - Replace sprintf() with sysfs_emit() in sysfs show in the cpufreq
     schedutil governor and fix a self-contradictory comment in
     sugov_iowait_apply() (Zhongqiu Han)

   - Fix the usage example for the sampling_rate tunable of the ondemand
     cpufreq governor in admin-guide (wangxiaodong)

   - Avoid using deep idle states during initialization in the
     intel_idle driver to work around device handling issues (Rafael
     Wysocki)

   - Fix and refactor the ACPI processor driver code related to ACPI
     _LPI support and add ACPI _LPI support to intel_idle based on that
     ACPI processor driver update (Rafael Wysocki)

   - Backup and restore governor for cpufreq sptests (Yiwei Lin)

   - Remove unnecessary sudo from quick_shuffle() and remove unused
     local variables from switch_show_governor() in cpufreq selftests
     (Jinseok Kim)

   - Rename the PM core module parameter prefix to "pm" and allow the PM
     transition (DPM) watchdog to be disabled by default (Tzung-Bi Shih)

   - Fix off-by-one in wakelocks number limit check in the system sleep
     sysfs interface (Haowen Tu)

   - Remove kernel-doc markings from helper descriptions in the core
     hibernation code (Adi Nata)

   - Use %pe to print error pointer values in the hibernation core
     (Ronan Marchal)

   - Fix memory leak in snapshot_write_next() error path (Malaya Kumar
     Rout)

   - Delay allocating and linking the next swap_map_page in the
     hibernation image saving code until another image page actually
     needs to be recorded (Haesung Kim)

   - Fix cleanup ordering around scope-based pointers in OPP (Gregor
     Herburger).

   - Use clk_get_optional() for optional clocks in OPP (Praveen Talari).

   - Stop setting runtime_error on runtime resume callback failures to
     allow drivers to recover from resume issues (Praveen Talari)

   - Handle PMU registration failure during probe in the intel_rapl_tpmi
     driver (Sumeet Pawnikar)

   - Avoid optional imports in intel_pstate_tracer unless they are
     really needed (Yousef Alhouseen)

   - Add generic CPPC performance display to the cpupower utility, build
     and call CPPC information on non-AMD processors, make cpupower
     print kernel and hardware frequency information, and add libm to
     cpupower for generic CPPC view (Jeremy Linton)

   - Remove conditional return with no effect from cpupower (Sang-Heon
     Jeon)"

* tag 'pm-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
  cpufreq: imx6q: fix out-of-bounds write when probed more than once
  cpufreq: imx6q: fix devres accumulation across driver rebind
  rust: cpufreq: Fix temporary write in Registration::bios_limit_callback
  rust: cpufreq: Add CPUFREQ_TABLE_END as last table entry in TableBuilder::to_table
  opp: Use clk_get_optional() to avoid leaving opp_table->clk as an error pointer
  intel_idle: Avoid using deep idle states during initialization
  cpupower: remove conditional return with no effect
  cpufreq: intel_pstate: Adjust policy->cur in active mode to policy
  cpufreq/amd-pstate: Document missing kernel-doc members
  cpufreq/amd-pstate-ut: Add unit test for CPPC Performance Priority
  cpufreq/amd-pstate-ut: Add unit test for "dynamic" EPP mode
  cpufreq/amd-pstate: Reduce the scope of exported symbols
  Documentation/amd-pstate: Update dynamic_epp documentation with new behavior
  cpufreq/amd-pstate: Remove "amd_dynamic_epp" cmdline and "dynamic_epp" sysfs
  cpufreq/amd-pstate: Add dynamic EPP as an "energy_performance_preference" mode
  cpufreq/amd-pstate: Extract platform profile to EPP conversion into a helper
  cpufreq/amd-pstate: Remove the defensive check for bios_min_perf
  cpufreq/amd-pstate: Set min_limit_freq based on bios_min_perf
  powercap: intel_rapl_tpmi: Handle PMU registration failure during probe
  PM: sleep: Allow disabling DPM watchdog by default
  ...
2026-08-18 08:47:09 -07:00
arch ACPI support updates for 7.3-rc1 2026-08-18 08:29:30 -07:00
block fscrypt updates for 7.3 2026-08-17 19:04:16 -07:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto Crypto library updates for 7.3 2026-08-17 19:16:42 -07:00
Documentation Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
drivers Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
fs Crypto library updates for 7.3 2026-08-17 19:16:42 -07:00
include Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
init vfs-7.3-rc1.misc 2026-08-17 12:56:12 -07:00
io_uring io_uring/rsrc: reject overflowing regvec bvec byte counts 2026-08-12 19:53:35 -06:00
ipc vfs-7.3-rc1.lookup 2026-08-17 12:03:34 -07:00
kernel Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
lib linux_kselftest-kunit-7.3-rc1 2026-08-17 19:44:06 -07:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm vfs-7.3-rc1.lookup 2026-08-17 12:03:34 -07:00
net Crypto library updates for 7.3 2026-08-17 19:16:42 -07:00
rust Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
samples samples/damon/mtier: error out for zero quota goal target values 2026-08-04 20:02:02 -07:00
scripts Crypto library tests for 7.3 2026-08-17 19:29:41 -07:00
security selinux/stable-7.2 PR 20260805 2026-08-05 13:40:11 -07:00
sound ASoC: Fixes for v7.2 2026-08-13 15:32:36 +02:00
tools Power management updates for 7.3-rc1 2026-08-18 08:47:09 -07:00
usr kbuild: uapi: also test UAPI headers against C++ compilers 2026-03-25 13:24:42 +01:00
virt KVM/arm64 fixes for 7.2, take #2 2026-07-15 12:13:30 +02:00
.clang-format clang-format: fix formatting of guard() and scoped_guard() statements 2026-05-28 21:24:41 -07:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add myself 2026-04-02 16:48:25 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore SPDX patches for 7.2-rc1 2026-06-22 12:06:22 -07:00
.mailmap There is a known WiFi/mt76 regression, waiting for a complete fix that 2026-08-13 08:37:26 -07:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Add Wolfram Sang 2026-07-14 16:34:04 +02:00
Kbuild checksyscalls: move instance functionality into generic code 2026-04-05 09:21:32 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS vfs-7.3-rc1.efs 2026-08-17 08:55:58 -07:00
Makefile Linux 7.2 2026-08-16 14:32:26 -07:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -07:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst