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Di Shen e95fa74047 thermal: gov_power_allocator: avoid inability to reset a cdev
Commit 0952177f2a ("thermal/core/power_allocator: Update once
cooling devices when temp is low") adds an update flag to avoid
triggering a thermal event when there is no need, and the thermal
cdev is updated once when the temperature is low.

But when the trips are writable, and switch_on_temp is set to be a
higher value, the cooling device state may not be reset to 0,
because last_temperature is smaller than switch_on_temp.

For example:
First:
switch_on_temp=70 control_temp=85;
Then userspace change the trip_temp:
switch_on_temp=45 control_temp=55 cur_temp=54

Then userspace reset the trip_temp:
switch_on_temp=70 control_temp=85 cur_temp=57 last_temp=54

At this time, the cooling device state should be reset to 0.
However, because cur_temp(57) < switch_on_temp(70)
last_temp(54) < switch_on_temp(70)  ---->  update = false,
update is false, the cooling device state can not be reset.

Using the observation that tz->passive can also be regarded as the
temperature status, set the update flag to the tz->passive value.

When the temperature drops below switch_on for the first time, the
states of cooling devices can be reset once, and tz->passive is updated
to 0. In the next round, because tz->passive is 0, cdev->state will not
be updated.

By using the tz->passive value as the "update" flag, the issue above
can be solved, and the cooling devices can be updated only once when the
temperature is low.

Fixes: 0952177f2a ("thermal/core/power_allocator: Update once cooling devices when temp is low")
Cc: 5.13+ <stable@vger.kernel.org> # 5.13+
Suggested-by: Wei Wang <wvw@google.com>
Signed-off-by: Di Shen <di.shen@unisoc.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-12 15:38:23 +01:00
Documentation dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Clean up examples 2024-01-02 09:33:18 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch - Ignore invalid x2APIC entries in order to not waste per-CPU data 2023-11-19 13:46:17 -08:00
block blk-mq: make sure active queue usage is held for bio_integrity_prep() 2023-11-13 08:52:52 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression in ahash and hides the Kconfig sub-options for the jitter RNG. 2023-11-09 17:04:58 -08:00
drivers thermal: gov_power_allocator: avoid inability to reset a cdev 2024-01-12 15:38:23 +01:00
fs Bug fixes for 6.7-rc2: 2023-11-18 11:28:28 -08:00
include thermal: core: Use kstrdup_const() during cooling device registration 2024-01-12 15:38:23 +01:00
init As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
io_uring io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrieval 2023-11-15 06:35:46 -07:00
ipc Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
kernel reboot: Introduce thermal_zone_device_critical_reboot() 2024-01-02 09:33:18 +01:00
lib Zstd fixes for v6.7 2023-11-14 23:35:31 -05:00
mm mm: more ptep_get() conversion 2023-11-15 15:30:09 -08:00
net netfilter pull request 23-11-15 2023-11-16 11:02:52 +01:00
rust Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
samples Landlock updates for v6.7-rc1 2023-11-03 09:28:53 -10:00
scripts Kbuild fixes for v6.7 2023-11-19 13:54:28 -08:00
security + Features 2023-11-03 09:48:17 -10:00
sound sound fixes for 6.7-rc2 2023-11-17 09:05:31 -05:00
tools tools/thermal/tmon: Fix compilation warning for wrong format 2024-01-02 09:33:19 +01:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS - Ignore invalid x2APIC entries in order to not waste per-CPU data 2023-11-19 13:46:17 -08:00
Makefile Linux 6.7-rc2 2023-11-19 15:02:14 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.