<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux/thermal.h, branch v6.8.4</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'thermal-6.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2024-01-17T22:47:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-17T22:47:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8e6ba025f5e45cb0821298919b0e07130cef877'/>
<id>d8e6ba025f5e45cb0821298919b0e07130cef877</id>
<content type='text'>
Pull more thermal control updates from Rafael Wysocki:
 "These add support for debugfs-based diagnostics to the thermal core,
  simplify the thermal netlink API, fix system-wide PM support in the
  Intel HFI driver and clean up some code.

  Specifics:

   - Add debugfs-based diagnostics support to the thermal core (Daniel
     Lezcano, Dan Carpenter)

   - Fix a power allocator thermal governor issue preventing it from
     resetting cooling devices sometimes (Di Shen)

   - Simplify the thermal netlink API and clean up related code (Rafael
     J. Wysocki)

   - Make the Intel HFI driver support hibernation and deep suspend
     properly (Ricardo Neri)"

* tag 'thermal-6.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal/debugfs: Unlock on error path in thermal_debug_tz_trip_up()
  thermal: intel: hfi: Add syscore callbacks for system-wide PM
  thermal: gov_power_allocator: avoid inability to reset a cdev
  thermal: helpers: Rearrange thermal_cdev_set_cur_state()
  thermal: netlink: Rework notify API for cooling devices
  thermal: core: Use kstrdup_const() during cooling device registration
  thermal/debugfs: Add thermal debugfs information for mitigation episodes
  thermal/debugfs: Add thermal cooling device debugfs information
  thermal: netlink: Pass thermal zone pointer to notify routines
  thermal: netlink: Drop thermal_notify_tz_trip_add/delete()
  thermal: netlink: Pass pointers to thermal_notify_tz_trip_up/down()
  thermal: netlink: Pass pointers to thermal_notify_tz_trip_change()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more thermal control updates from Rafael Wysocki:
 "These add support for debugfs-based diagnostics to the thermal core,
  simplify the thermal netlink API, fix system-wide PM support in the
  Intel HFI driver and clean up some code.

  Specifics:

   - Add debugfs-based diagnostics support to the thermal core (Daniel
     Lezcano, Dan Carpenter)

   - Fix a power allocator thermal governor issue preventing it from
     resetting cooling devices sometimes (Di Shen)

   - Simplify the thermal netlink API and clean up related code (Rafael
     J. Wysocki)

   - Make the Intel HFI driver support hibernation and deep suspend
     properly (Ricardo Neri)"

* tag 'thermal-6.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal/debugfs: Unlock on error path in thermal_debug_tz_trip_up()
  thermal: intel: hfi: Add syscore callbacks for system-wide PM
  thermal: gov_power_allocator: avoid inability to reset a cdev
  thermal: helpers: Rearrange thermal_cdev_set_cur_state()
  thermal: netlink: Rework notify API for cooling devices
  thermal: core: Use kstrdup_const() during cooling device registration
  thermal/debugfs: Add thermal debugfs information for mitigation episodes
  thermal/debugfs: Add thermal cooling device debugfs information
  thermal: netlink: Pass thermal zone pointer to notify routines
  thermal: netlink: Drop thermal_notify_tz_trip_add/delete()
  thermal: netlink: Pass pointers to thermal_notify_tz_trip_up/down()
  thermal: netlink: Pass pointers to thermal_notify_tz_trip_change()
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: core: Use kstrdup_const() during cooling device registration</title>
<updated>2024-01-12T14:38:23+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2024-01-05T13:45:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=57a427c81c322c5f0cdfe7c46cdee553d18b1ec6'/>
<id>57a427c81c322c5f0cdfe7c46cdee553d18b1ec6</id>
<content type='text'>
Some *thermal_cooling_device_register() calls pass a string literal as
the 'type' parameter, so kstrdup_const() can be used instead of
kstrdup() to avoid a memory allocation in such cases.

Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some *thermal_cooling_device_register() calls pass a string literal as
the 'type' parameter, so kstrdup_const() can be used instead of
kstrdup() to avoid a memory allocation in such cases.

Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal/debugfs: Add thermal cooling device debugfs information</title>
<updated>2024-01-12T14:34:56+00:00</updated>
<author>
<name>Daniel Lezcano</name>
<email>daniel.lezcano@linaro.org</email>
</author>
<published>2024-01-09T09:41:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=755113d7678681a137c330f7997ceb680adb644e'/>
<id>755113d7678681a137c330f7997ceb680adb644e</id>
<content type='text'>
The thermal framework does not have any debug information except a
sysfs stat which is a bit controversial. This one allocates big chunks
of memory for every cooling devices with a high number of states and
could represent on some systems in production several megabytes of
memory for just a portion of it. As the sysfs is limited to a page
size, the output is not exploitable with large data array and gets
truncated.

The patch provides the same information than sysfs except the
transitions are dynamically allocated, thus they won't show more
events than the ones which actually occurred. There is no longer a
size limitation and it opens the field for more debugging information
where the debugfs is designed for, not sysfs.

The thermal debugfs directory structure tries to stay consistent with
the sysfs one but in a very simplified way:

thermal/
 -- cooling_devices
    |-- 0
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 1
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 2
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 3
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    `-- 4
        |-- clear
        |-- time_in_state_ms
        |-- total_trans
        `-- trans_table

The content of the files in the cooling devices directory is the same
as the sysfs one except for the trans_table which has the following
format:

Transition	Hits
1-&gt;0      	246
0-&gt;1      	246
2-&gt;1      	632
1-&gt;2      	632
3-&gt;2      	98
2-&gt;3      	98

Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
[ rjw: White space fixups, rebase ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The thermal framework does not have any debug information except a
sysfs stat which is a bit controversial. This one allocates big chunks
of memory for every cooling devices with a high number of states and
could represent on some systems in production several megabytes of
memory for just a portion of it. As the sysfs is limited to a page
size, the output is not exploitable with large data array and gets
truncated.

The patch provides the same information than sysfs except the
transitions are dynamically allocated, thus they won't show more
events than the ones which actually occurred. There is no longer a
size limitation and it opens the field for more debugging information
where the debugfs is designed for, not sysfs.

The thermal debugfs directory structure tries to stay consistent with
the sysfs one but in a very simplified way:

thermal/
 -- cooling_devices
    |-- 0
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 1
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 2
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 3
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    `-- 4
        |-- clear
        |-- time_in_state_ms
        |-- total_trans
        `-- trans_table

The content of the files in the cooling devices directory is the same
as the sysfs one except for the trans_table which has the following
format:

Transition	Hits
1-&gt;0      	246
0-&gt;1      	246
2-&gt;1      	632
1-&gt;2      	632
3-&gt;2      	98
2-&gt;3      	98

Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
[ rjw: White space fixups, rebase ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'thermal-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2024-01-10T00:20:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-10T00:20:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7f73ba68cf67ef533783013f863d750c5736f957'/>
<id>7f73ba68cf67ef533783013f863d750c5736f957</id>
<content type='text'>
Pull thermal control updates from Rafael Wysocki:
 "These add support for the D1/T113s THS controller to the sun8i driver
  and a DT-based mechanism for platforms to indicate a preference to
  reboot (instead of shutting down) on crossing a critical trip point,
  fix issues, make other improvements (in the IPA governor, the Intel
  HFI driver, the exynos driver and the thermal netlink interface among
  other places) and clean up code.

  One long-standing issue addressed here is that trip point crossing
  notifications sent to user space might be unreliable due to the
  incorrect handling of trip point hysteresis in the thermal core:
  multiple notifications might be sent for the same event or there might
  be events without any notification at all.

  Specifics:

   - Add dynamic thresholds for trip point crossing detection to prevent
     trip point crossing notifications from being sent at incorrect
     times or not at all in some cases (Rafael J. Wysocki)

   - Fix synchronization issues related to the resume of thermal zones
     during a system-wide resume and allow thermal zones to be resumed
     concurrently (Rafael J. Wysocki)

   - Modify the thermal zone unregistration to wait for the given zone
     to go away completely before returning to the caller and rework the
     sysfs interface for trip points on top of that (Rafael J. Wysocki)

   - Fix a possible NULL pointer dereference in thermal zone
     registration error path (Rafael J. Wysocki)

   - Clean up the IPA thermal governor and modify it (with the help of a
     new governor callback) to avoid allocating and freeing memory every
     time its throttling callback is invoked (Lukasz Luba)

   - Make the IPA thermal governor handle thermal instance weight
     changes via sysfs correctly (Lukasz Luba)

   - Update the thermal netlink code to avoid sending messages if there
     are no recipients (Stanislaw Gruszka)

   - Convert Mediatek Thermal to the json-schema (Rafał Miłecki)

   - Fix thermal DT bindings issue on Loongson (Binbin Zhou)

   - Fix returning NULL instead of -ENODEV during thermal probe on
     Loogsoon (Binbin Zhou)

   - Add thermal DT binding for tsens on the SM8650 platform (Neil
     Armstrong)

   - Add reboot on the critical trip point crossing option feature
     (Fabio Estevam)

   - Use DEFINE_SIMPLE_DEV_PM_OPS do define PM functions for thermal
     suspend/resume on AmLogic (Uwe Kleine-König)

   - Add D1/T113s THS controller support to the Sun8i thermal control
     driver (Maxim Kiselev)

   - Fix example in the thermal DT binding for QCom SPMI (Johan Hovold)

   - Fix compilation warning in the tmon utility (Florian Eckert)

   - Add support for interrupt-based thermal configuration on Exynos
     along with a set of related cleanups (Mateusz Majewski)

   - Make the Intel HFI thermal driver enable an HFI instance (eg.
     processor package) from its first online CPU and disable it when
     the last CPU in it goes offline (Ricardo Neri)

   - Fix a kernel-doc warning and a spello in the cpuidle_cooling
     thermal driver (Randy Dunlap)

   - Move the .get_temp() thermal zone callback presence check to the
     thermal zone registration code (Daniel Lezcano)

   - Use the for_each_trip() macro for trip points table walks in a few
     places in the thermal core (Rafael J. Wysocki)

   - Make all trip point updates (via sysfs as well as from the platform
     firmware) trigger trip change notifications (Rafael J. Wysocki)

   - Drop redundant code from the thermal core and make one function in
     it take a const pointer argument (Rafael J. Wysocki)"

* tag 'thermal-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits)
  thermal: trip: Constify thermal zone argument of thermal_zone_trip_id()
  thermal: intel: hfi: Disable an HFI instance when all its CPUs go offline
  thermal: intel: hfi: Enable an HFI instance from its first online CPU
  thermal: intel: hfi: Refactor enabling code into helper functions
  thermal/drivers/exynos: Use set_trips ops
  thermal/drivers/exynos: Use BIT wherever possible
  thermal/drivers/exynos: Split initialization of TMU and the thermal zone
  thermal/drivers/exynos: Stop using the threshold mechanism on Exynos 4210
  thermal/drivers/exynos: Simplify regulator (de)initialization
  thermal/drivers/exynos: Handle devm_regulator_get_optional return value correctly
  thermal/drivers/exynos: Wwitch from workqueue-driven interrupt handling to threaded interrupts
  thermal/drivers/exynos: Drop id field
  thermal/drivers/exynos: Remove an unnecessary field description
  tools/thermal/tmon: Fix compilation warning for wrong format
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Clean up examples
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Fix example node names
  thermal/drivers/sun8i: Add D1/T113s THS controller support
  dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller
  thermal: amlogic: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
  thermal: amlogic: Make amlogic_thermal_disable() return void
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull thermal control updates from Rafael Wysocki:
 "These add support for the D1/T113s THS controller to the sun8i driver
  and a DT-based mechanism for platforms to indicate a preference to
  reboot (instead of shutting down) on crossing a critical trip point,
  fix issues, make other improvements (in the IPA governor, the Intel
  HFI driver, the exynos driver and the thermal netlink interface among
  other places) and clean up code.

  One long-standing issue addressed here is that trip point crossing
  notifications sent to user space might be unreliable due to the
  incorrect handling of trip point hysteresis in the thermal core:
  multiple notifications might be sent for the same event or there might
  be events without any notification at all.

  Specifics:

   - Add dynamic thresholds for trip point crossing detection to prevent
     trip point crossing notifications from being sent at incorrect
     times or not at all in some cases (Rafael J. Wysocki)

   - Fix synchronization issues related to the resume of thermal zones
     during a system-wide resume and allow thermal zones to be resumed
     concurrently (Rafael J. Wysocki)

   - Modify the thermal zone unregistration to wait for the given zone
     to go away completely before returning to the caller and rework the
     sysfs interface for trip points on top of that (Rafael J. Wysocki)

   - Fix a possible NULL pointer dereference in thermal zone
     registration error path (Rafael J. Wysocki)

   - Clean up the IPA thermal governor and modify it (with the help of a
     new governor callback) to avoid allocating and freeing memory every
     time its throttling callback is invoked (Lukasz Luba)

   - Make the IPA thermal governor handle thermal instance weight
     changes via sysfs correctly (Lukasz Luba)

   - Update the thermal netlink code to avoid sending messages if there
     are no recipients (Stanislaw Gruszka)

   - Convert Mediatek Thermal to the json-schema (Rafał Miłecki)

   - Fix thermal DT bindings issue on Loongson (Binbin Zhou)

   - Fix returning NULL instead of -ENODEV during thermal probe on
     Loogsoon (Binbin Zhou)

   - Add thermal DT binding for tsens on the SM8650 platform (Neil
     Armstrong)

   - Add reboot on the critical trip point crossing option feature
     (Fabio Estevam)

   - Use DEFINE_SIMPLE_DEV_PM_OPS do define PM functions for thermal
     suspend/resume on AmLogic (Uwe Kleine-König)

   - Add D1/T113s THS controller support to the Sun8i thermal control
     driver (Maxim Kiselev)

   - Fix example in the thermal DT binding for QCom SPMI (Johan Hovold)

   - Fix compilation warning in the tmon utility (Florian Eckert)

   - Add support for interrupt-based thermal configuration on Exynos
     along with a set of related cleanups (Mateusz Majewski)

   - Make the Intel HFI thermal driver enable an HFI instance (eg.
     processor package) from its first online CPU and disable it when
     the last CPU in it goes offline (Ricardo Neri)

   - Fix a kernel-doc warning and a spello in the cpuidle_cooling
     thermal driver (Randy Dunlap)

   - Move the .get_temp() thermal zone callback presence check to the
     thermal zone registration code (Daniel Lezcano)

   - Use the for_each_trip() macro for trip points table walks in a few
     places in the thermal core (Rafael J. Wysocki)

   - Make all trip point updates (via sysfs as well as from the platform
     firmware) trigger trip change notifications (Rafael J. Wysocki)

   - Drop redundant code from the thermal core and make one function in
     it take a const pointer argument (Rafael J. Wysocki)"

* tag 'thermal-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits)
  thermal: trip: Constify thermal zone argument of thermal_zone_trip_id()
  thermal: intel: hfi: Disable an HFI instance when all its CPUs go offline
  thermal: intel: hfi: Enable an HFI instance from its first online CPU
  thermal: intel: hfi: Refactor enabling code into helper functions
  thermal/drivers/exynos: Use set_trips ops
  thermal/drivers/exynos: Use BIT wherever possible
  thermal/drivers/exynos: Split initialization of TMU and the thermal zone
  thermal/drivers/exynos: Stop using the threshold mechanism on Exynos 4210
  thermal/drivers/exynos: Simplify regulator (de)initialization
  thermal/drivers/exynos: Handle devm_regulator_get_optional return value correctly
  thermal/drivers/exynos: Wwitch from workqueue-driven interrupt handling to threaded interrupts
  thermal/drivers/exynos: Drop id field
  thermal/drivers/exynos: Remove an unnecessary field description
  tools/thermal/tmon: Fix compilation warning for wrong format
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Clean up examples
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Fix example node names
  thermal/drivers/sun8i: Add D1/T113s THS controller support
  dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller
  thermal: amlogic: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
  thermal: amlogic: Make amlogic_thermal_disable() return void
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal/sysfs: Update governors when the 'weight' has changed</title>
<updated>2023-12-29T17:01:01+00:00</updated>
<author>
<name>Lukasz Luba</name>
<email>lukasz.luba@arm.com</email>
</author>
<published>2023-12-20T23:17:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bfc57bd1685981730bfe9802d9de7603a0a43bc4'/>
<id>bfc57bd1685981730bfe9802d9de7603a0a43bc4</id>
<content type='text'>
Support governors update when the thermal instance's weight has changed.
This allows to adjust internal state for the governor.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
[ rjw: Add two empty code lines aroung the locking ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Support governors update when the thermal instance's weight has changed.
This allows to adjust internal state for the governor.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
[ rjw: Add two empty code lines aroung the locking ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: core: Add governor callback for thermal zone change</title>
<updated>2023-12-29T17:01:00+00:00</updated>
<author>
<name>Lukasz Luba</name>
<email>lukasz.luba@arm.com</email>
</author>
<published>2023-12-20T23:17:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a8c959402d4dd6823918b33828d79900ae58c700'/>
<id>a8c959402d4dd6823918b33828d79900ae58c700</id>
<content type='text'>
Add a new callback to the struct thermal_governor. It can be used for
updating governors when there is a change in the thermal zone internals,
e.g. thermal cooling device is bind to the thermal zone.

That makes possible to move some heavy operations like memory allocations
related to the number of cooling instances out of the throttle() callback.

Both callback code paths (throttle() and update_tz()) are protected with
the same thermal zone lock, which guaranties the consistency.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a new callback to the struct thermal_governor. It can be used for
updating governors when there is a change in the thermal zone internals,
e.g. thermal cooling device is bind to the thermal zone.

That makes possible to move some heavy operations like memory allocations
related to the number of cooling instances out of the throttle() callback.

Both callback code paths (throttle() and update_tz()) are protected with
the same thermal zone lock, which guaranties the consistency.

Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: core: Fix thermal zone suspend-resume synchronization</title>
<updated>2023-12-28T13:20:15+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-12-18T19:25:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e814173a8c4f432fd068b1c796f0416328c9d99'/>
<id>4e814173a8c4f432fd068b1c796f0416328c9d99</id>
<content type='text'>
There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

 1. The resume code runs in a PM notifier which is invoked after user
    space has been thawed, so it can run concurrently with user space
    which can trigger a thermal zone device removal.  If that happens,
    the thermal zone resume code may use a stale pointer to the next
    list element and crash, because it does not hold thermal_list_lock
    while walking thermal_tz_list.

 2. The thermal zone resume code calls thermal_zone_device_init()
    outside the zone lock, so user space or an update triggered by
    the platform firmware may see an inconsistent state of a
    thermal zone leading to unexpected behavior.

 3. Clearing the in_suspend global variable in thermal_pm_notify()
    allows __thermal_zone_device_update() to continue for all thermal
    zones and it may as well run before the thermal_tz_list walk (or
    at any point during the list walk for that matter) and attempt to
    operate on a thermal zone that has not been resumed yet.  It may
    also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye &lt;bo.ye@mediatek.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

 1. The resume code runs in a PM notifier which is invoked after user
    space has been thawed, so it can run concurrently with user space
    which can trigger a thermal zone device removal.  If that happens,
    the thermal zone resume code may use a stale pointer to the next
    list element and crash, because it does not hold thermal_list_lock
    while walking thermal_tz_list.

 2. The thermal zone resume code calls thermal_zone_device_init()
    outside the zone lock, so user space or an update triggered by
    the platform firmware may see an inconsistent state of a
    thermal zone leading to unexpected behavior.

 3. Clearing the in_suspend global variable in thermal_pm_notify()
    allows __thermal_zone_device_update() to continue for all thermal
    zones and it may as well run before the thermal_tz_list walk (or
    at any point during the list walk for that matter) and attempt to
    operate on a thermal zone that has not been resumed yet.  It may
    also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye &lt;bo.ye@mediatek.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: trip: Send trip change notifications on all trip updates</title>
<updated>2023-12-13T11:37:01+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-12-05T19:18:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bdc22c8d52d70fc5655ab4dbf72fa79b034bb7b5'/>
<id>bdc22c8d52d70fc5655ab4dbf72fa79b034bb7b5</id>
<content type='text'>
The _store callbacks of the trip point temperature and hysteresis sysfs
attributes invoke thermal_notify_tz_trip_change() to send a notification
regarding the trip point change, but when trip points are updated by the
platform firmware, trip point change notifications are not sent.

To make the behavior after a trip point change more consistent,
modify all of the 3 places where trip point temperature is updated
to use a new function called thermal_zone_set_trip_temp() for this
purpose and make that function call thermal_notify_tz_trip_change().

Note that trip point hysteresis can only be updated via sysfs and
trip_point_hyst_store() calls thermal_notify_tz_trip_change() already,
so this code path need not be changed.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The _store callbacks of the trip point temperature and hysteresis sysfs
attributes invoke thermal_notify_tz_trip_change() to send a notification
regarding the trip point change, but when trip points are updated by the
platform firmware, trip point change notifications are not sent.

To make the behavior after a trip point change more consistent,
modify all of the 3 places where trip point temperature is updated
to use a new function called thermal_zone_set_trip_temp() for this
purpose and make that function call thermal_notify_tz_trip_change().

Note that trip point hysteresis can only be updated via sysfs and
trip_point_hyst_store() calls thermal_notify_tz_trip_change() already,
so this code path need not be changed.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: core: Make thermal_zone_device_unregister() return after freeing the zone</title>
<updated>2023-12-11T19:49:53+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-12-08T19:13:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4649620d9404d3aceb25891c24bab77143e3f21c'/>
<id>4649620d9404d3aceb25891c24bab77143e3f21c</id>
<content type='text'>
Make thermal_zone_device_unregister() wait until all of the references
to the given thermal zone object have been dropped and free it before
returning.

This guarantees that when thermal_zone_device_unregister() returns,
there is no leftover activity regarding the thermal zone in question
which is required by some of its callers (for instance, modular driver
code that wants to know when it is safe to let the module go away).

Subsequently, this will allow some confusing device_is_registered()
checks to be dropped from the thermal sysfs and core code.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-and-tested-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make thermal_zone_device_unregister() wait until all of the references
to the given thermal zone object have been dropped and free it before
returning.

This guarantees that when thermal_zone_device_unregister() returns,
there is no leftover activity regarding the thermal zone in question
which is required by some of its callers (for instance, modular driver
code that wants to know when it is safe to let the module go away).

Subsequently, this will allow some confusing device_is_registered()
checks to be dropped from the thermal sysfs and core code.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-and-tested-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal: sysfs: Rework the handling of trip point updates</title>
<updated>2023-12-06T20:29:52+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-12-05T12:24:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=be0a3600aa1ebe9d23243c91d41ab1a2d5091a9b'/>
<id>be0a3600aa1ebe9d23243c91d41ab1a2d5091a9b</id>
<content type='text'>
Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it.  However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.

Moreover, input processing need not be done under the thermal zone lock
in any of these functions.

Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.

While at it, make trip_point_hyst_store() reject negative hysteresis
values.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it.  However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.

Moreover, input processing need not be done under the thermal zone lock
in any of these functions.

Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.

While at it, make trip_point_hyst_store() reject negative hysteresis
values.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
