linux-stable.git/kernel/power/Kconfig, branch master Linux kernel stable tree PM: sleep: Allow disabling DPM watchdog by default 2026-07-23T13:46:34+00:00 Tzung-Bi Shih tzungbi@kernel.org 2026-07-20T03:08:21+00:00 dca82e209e5ced94b9e53c004a935bc44162073d Introduce the "dpm_watchdog_enabled" module parameter to allow the DPM watchdog to be enabled or disabled at boot time and runtime. Additionally, introduce the CONFIG_DPM_WATCHDOG_ENABLED Kconfig option to set the default value of the module parameter at compile time. The primary motivation for this configurability resolves around Android GKI (Generic Kernel Image). We want to enable CONFIG_DPM_WATCHDOG in the GKI so the feature is available. However, because the GKI is shared across many different devices, we don't want to inadvertently affect devices that are unaware of this feature. This provides a way to compile it in, but keep it disabled by default for those devices via the kernel command line or module parameters. To maintain backward compatibility, CONFIG_DPM_WATCHDOG_ENABLED relies on `default y`. Previously, the DPM watchdog was always active if CONFIG_DPM_WATCHDOG was set. Defaulting this new option to 'y' ensures that the behavior remains unchanged for existing users and defconfigs when they upgrade. Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Link: https://patch.msgid.link/20260720030821.2780257-3-tzungbi@kernel.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Introduce the "dpm_watchdog_enabled" module parameter to allow the DPM
watchdog to be enabled or disabled at boot time and runtime.

Additionally, introduce the CONFIG_DPM_WATCHDOG_ENABLED Kconfig option
to set the default value of the module parameter at compile time.

The primary motivation for this configurability resolves around Android
GKI (Generic Kernel Image).  We want to enable CONFIG_DPM_WATCHDOG in
the GKI so the feature is available.  However, because the GKI is shared
across many different devices, we don't want to inadvertently affect
devices that are unaware of this feature.  This provides a way to
compile it in, but keep it disabled by default for those devices via the
kernel command line or module parameters.

To maintain backward compatibility, CONFIG_DPM_WATCHDOG_ENABLED relies
on `default y`.  Previously, the DPM watchdog was always active if
CONFIG_DPM_WATCHDOG was set.  Defaulting this new option to 'y' ensures
that the behavior remains unchanged for existing users and defconfigs
when they upgrade.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260720030821.2780257-3-tzungbi@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: hibernate: make LZ4 available for hibernation compression 2026-05-26T11:42:17+00:00 l1rox3 l1rox3.developer@gmail.com 2026-05-20T08:12:54+00:00 2068d7715e947f0321bc676a44215d3983af4bbc Without this, CRYPTO_LZ4 had to be manually enabled in the config to use LZ4 for hibernation compression. Add the select so it gets pulled in automatically when hibernation is enabled, just like CRYPTO_LZO already does. Tested-by: l1rox3 <l1rox3.developer@gmail.com> Signed-off-by: l1rox3 <l1rox3.developer@gmail.com> Link: https://patch.msgid.link/20260520081254.13493-1-l1rox3.developer@gmail.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Without this, CRYPTO_LZ4 had to be manually enabled in the config
to use LZ4 for hibernation compression. Add the select so it gets
pulled in automatically when hibernation is enabled, just like
CRYPTO_LZO already does.

Tested-by: l1rox3 <l1rox3.developer@gmail.com>
Signed-off-by: l1rox3 <l1rox3.developer@gmail.com>
Link: https://patch.msgid.link/20260520081254.13493-1-l1rox3.developer@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: QoS: Introduce a CPU system wakeup QoS limit 2025-11-25T18:01:29+00:00 Ulf Hansson ulf.hansson@linaro.org 2025-11-25T11:26:42+00:00 a4e6512a79d8486dccf3e8b066e5d6bd5ff95446 Some platforms supports multiple low power states for CPUs that can be used when entering system-wide suspend. Currently we are always selecting the deepest possible state for the CPUs, which can break the system wakeup latency constraint that may be required for a use case. Let's take the first step towards addressing this problem, by introducing an interface for user space, that allows us to specify the CPU system wakeup QoS limit. Subsequent changes will start taking into account the new QoS limit. Reviewed-by: Dhruva Gole <d-gole@ti.com> Reviewed-by: Kevin Hilman (TI) <khilman@baylibre.com> Tested-by: Kevin Hilman (TI) <khilman@baylibre.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://patch.msgid.link/20251125112650.329269-2-ulf.hansson@linaro.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Some platforms supports multiple low power states for CPUs that can be used
when entering system-wide suspend. Currently we are always selecting the
deepest possible state for the CPUs, which can break the system wakeup
latency constraint that may be required for a use case.

Let's take the first step towards addressing this problem, by introducing
an interface for user space, that allows us to specify the CPU system
wakeup QoS limit. Subsequent changes will start taking into account the new
QoS limit.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Kevin Hilman (TI) <khilman@baylibre.com>
Tested-by: Kevin Hilman (TI) <khilman@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/20251125112650.329269-2-ulf.hansson@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: EM: Rework the depends on for CONFIG_ENERGY_MODEL 2025-03-07T14:23:46+00:00 Jeson Gao jeson.gao@unisoc.com 2025-03-07T13:23:49+00:00 17f08280cf89baf5e4620fc7af300082bcee7e24 Now not only CPUs can use energy efficiency models, but GPUs can also use. On the other hand, even with only one CPU, we can also use energy_model to align control in thermal. So remove the dependence of SMP, and add the DEVFREQ. Signed-off-by: Jeson Gao <jeson.gao@unisoc.com> [Added missing SMP config option in DTPM_CPU dependency] Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://patch.msgid.link/20250307132649.4056210-1-lukasz.luba@arm.com [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Now not only CPUs can use energy efficiency models, but GPUs
can also use. On the other hand, even with only one CPU, we can also
use energy_model to align control in thermal.
So remove the dependence of SMP, and add the DEVFREQ.

Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
[Added missing SMP config option in DTPM_CPU dependency]
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20250307132649.4056210-1-lukasz.luba@arm.com
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: sleep: Allow configuring the DPM watchdog to warn earlier than panic 2025-01-14T20:23:57+00:00 Douglas Anderson dianders@chromium.org 2025-01-09T20:59:58+00:00 56cabb937f8f6091c231bdbc17c0d0a10130fb5d Allow configuring the DPM watchdog to warn about slow suspend/resume functions without causing a system panic(). This allows you to set the DPM_WATCHDOG_WARNING_TIMEOUT to something like 5 or 10 seconds to get warnings about slow suspend/resume functions that eventually succeed. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Tomasz Figa <tfiga@chromium.org> Link: https://patch.msgid.link/20250109125957.v2.1.I4554f931b8da97948f308ecc651b124338ee9603@changeid [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Allow configuring the DPM watchdog to warn about slow suspend/resume
functions without causing a system panic(). This allows you to set the
DPM_WATCHDOG_WARNING_TIMEOUT to something like 5 or 10 seconds to get
warnings about slow suspend/resume functions that eventually succeed.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://patch.msgid.link/20250109125957.v2.1.I4554f931b8da97948f308ecc651b124338ee9603@changeid
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: hibernate: Add support for LZ4 compression for hibernation 2024-02-05T13:30:35+00:00 Nikhil V quic_nprakash@quicinc.com 2024-01-22T13:15:27+00:00 8bc29736357e7f9a6bd0d16b57b5612197e1924b Extend the support for LZ4 compression to be used with hibernation. The main idea is that different compression algorithms have different characteristics and hibernation may benefit when it uses any of these algorithms: a default algorithm, having higher compression rate but is slower(compression/decompression) and a secondary algorithm, that is faster(compression/decompression) but has lower compression rate. LZ4 algorithm has better decompression speeds over LZO. This reduces the hibernation image restore time. As per test results: LZO LZ4 Size before Compression(bytes) 682696704 682393600 Size after Compression(bytes) 146502402 155993547 Decompression Rate 335.02 MB/s 501.05 MB/s Restore time 4.4s 3.8s LZO is the default compression algorithm used for hibernation. Enable CONFIG_HIBERNATION_COMP_LZ4 to set the default compressor as LZ4. Signed-off-by: Nikhil V <quic_nprakash@quicinc.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Extend the support for LZ4 compression to be used with hibernation.
The main idea is that different compression algorithms
have different characteristics and hibernation may benefit when it uses
any of these algorithms: a default algorithm, having higher
compression rate but is slower(compression/decompression) and a
secondary algorithm, that is faster(compression/decompression) but has
lower compression rate.

LZ4 algorithm has better decompression speeds over LZO. This reduces
the hibernation image restore time.
As per test results:
                                    LZO             LZ4
Size before Compression(bytes)   682696704       682393600
Size after Compression(bytes)    146502402       155993547
Decompression Rate               335.02 MB/s     501.05 MB/s
Restore time                       4.4s             3.8s

LZO is the default compression algorithm used for hibernation. Enable
CONFIG_HIBERNATION_COMP_LZ4 to set the default compressor as LZ4.

Signed-off-by: Nikhil V <quic_nprakash@quicinc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: hibernate: Move to crypto APIs for LZO compression 2024-02-05T13:28:54+00:00 Nikhil V quic_nprakash@quicinc.com 2024-01-22T13:15:26+00:00 a06c6f5d3cc90b3b070d7b99979d57238db77a86 Currently for hibernation, LZO is the only compression algorithm available and uses the existing LZO library calls. However, there is no flexibility to switch to other algorithms which provides better results. The main idea is that different compression algorithms have different characteristics and hibernation may benefit when it uses alternate algorithms. By moving to crypto based APIs, it lays a foundation to use other compression algorithms for hibernation. There are no functional changes introduced by this approach. Signed-off-by: Nikhil V <quic_nprakash@quicinc.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Currently for hibernation, LZO is the only compression algorithm
available and uses the existing LZO library calls. However, there
is no flexibility to switch to other algorithms which provides better
results. The main idea is that different compression algorithms have
different characteristics and hibernation may benefit when it uses
alternate algorithms.

By moving to crypto based APIs, it lays a foundation to use other
compression algorithms for hibernation. There are no functional changes
introduced by this approach.

Signed-off-by: Nikhil V <quic_nprakash@quicinc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM: sleep: Remove "select SRCU" 2023-01-20T16:53:07+00:00 Paul E. McKenney paulmck@kernel.org 2023-01-13T00:11:28+00:00 52e0452b413d885d5ab7e3ae85287d67f5a286b2 Now that the SRCU Kconfig option is unconditionally selected, there is no longer any point in selecting it. Therefore, remove the "select SRCU" Kconfig statements. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it.  Therefore, remove the "select SRCU"
Kconfig statements.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig 2022-07-01T08:39:20+00:00 Kalesh Singh kaleshsingh@google.com 2022-06-30T19:12:29+00:00 261e224d6a5c43e2bb8a07b7662f9b4ec425cfec Systems that initiate frequent suspend/resume from userspace can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP config. This allows for certain sleep-sensitive code (wireguard/rng) to decide on what preparatory work should be performed (or not) in their pm_notification callbacks. This patch was prompted by the discussion at [1] which attempts to remove CONFIG_ANDROID that currently guards these code paths. [1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/ Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Systems that initiate frequent suspend/resume from userspace
can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP
config.

This allows for certain sleep-sensitive code (wireguard/rng) to
decide on what preparatory work should be performed (or not) in
their pm_notification callbacks.

This patch was prompted by the discussion at [1] which attempts
to remove CONFIG_ANDROID that currently guards these code paths.

[1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/

Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM: sleep: remove trailing spaces and tabs 2021-06-11T16:49:09+00:00 Zhen Lei thunder.leizhen@huawei.com 2021-06-08T07:44:37+00:00 03466883a0fdb5c38f2907b027565b9f253688a8 Run the following command to find and remove the trailing spaces and tabs: $ find kernel/power/ -type f | xargs sed -r -i 's/[ \t]+$//' Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Run the following command to find and remove the trailing spaces and tabs:

$ find kernel/power/ -type f | xargs sed -r -i 's/[ \t]+$//'

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>