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Ido Schimmel 5601ef91fb mlxsw: core_thermal: Use static trip points for transceiver modules
The driver registers a thermal zone for each transceiver module and
tries to set the trip point temperatures according to the thresholds
read from the transceiver. If a threshold cannot be read or if a
transceiver is unplugged, the trip point temperature is set to zero,
which means that it is disabled as far as the thermal subsystem is
concerned.

A recent change in the thermal core made it so that such trip points are
no longer marked as disabled, which lead the thermal subsystem to
incorrectly set the associated cooling devices to the their maximum
state [1]. A fix to restore this behavior was merged in commit
f1b80a3878 ("thermal: core: Restore behavior regarding invalid trip
points"). However, the thermal maintainer suggested to not rely on this
behavior and instead always register a valid array of trip points [2].

Therefore, create a static array of trip points with sane defaults
(suggested by Vadim) and register it with the thermal zone of each
transceiver module. User space can choose to override these defaults
using the thermal zone sysfs interface since these files are writeable.

Before:

 $ cat /sys/class/thermal/thermal_zone11/type
 mlxsw-module11
 $ cat /sys/class/thermal/thermal_zone11/trip_point_*_temp
 65000
 75000
 80000

After:

 $ cat /sys/class/thermal/thermal_zone11/type
 mlxsw-module11
 $ cat /sys/class/thermal/thermal_zone11/trip_point_*_temp
 55000
 65000
 80000

Also tested by reverting commit f1b80a3878 ("thermal: core: Restore
behavior regarding invalid trip points") and making sure that the
associated cooling devices are not set to their maximum state.

[1] https://lore.kernel.org/linux-pm/ZA3CFNhU4AbtsP4G@shredder/
[2] https://lore.kernel.org/linux-pm/f78e6b70-a963-c0ca-a4b2-0d4c6aeef1fb@linaro.org/

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-02 13:42:30 +01:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-03-30 14:43:03 -07:00
block block: remove obsolete config BLOCK_COMPAT 2023-03-16 09:35:44 -06:00
certs Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
crypto asymmetric_keys: log on fatal failures in PE/pkcs7 2023-03-21 16:23:56 +00:00
Documentation Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 2023-03-31 21:41:11 -07:00
drivers mlxsw: core_thermal: Use static trip points for transceiver modules 2023-04-02 13:42:30 +01:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-03-30 14:43:03 -07:00
include net: minor reshuffle of napi_struct 2023-04-02 13:27:17 +01:00
init bootconfig: Change message if no bootconfig with CONFIG_BOOT_CONFIG_FORCE=y 2023-03-22 22:21:43 +09:00
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LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 21 hotfixes, 8 of which are cc:stable. 11 are for MM, the remainder are 2023-03-24 18:06:11 -07:00
net netfilter updates for net-next 2023-03-31 10:39:33 -07:00
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sound ALSA: hda/realtek: Add quirk for Lenovo ZhaoYang CF4620Z 2023-03-29 14:45:07 +02:00
tools tools: ynl: ethtool testing tool 2023-03-30 23:29:57 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM/riscv changes for 6.3 2023-02-15 12:33:28 -05:00
.clang-format cpumask: re-introduce constant-sized cpumask optimizations 2023-03-05 14:30:34 -08:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for *.dtso files 2023-02-26 15:28:23 +09:00
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COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS There is no particular theme here - mainly quick hits all over the tree. 2023-02-23 17:55:40 -08:00
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 Major stack changes: 2023-03-30 23:52:20 -07:00
Makefile Linux 6.3-rc4 2023-03-26 14:40:20 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.