The patch titled
Subject: docs: thermal: sync hardware protection doc with code
has been added to the -mm mm-nonmm-unstable branch. Its filename is
docs-thermal-sync-hardware-protection-doc-with-code.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/docs-thermal-sync-hardware-protection-doc-with-code.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Subject: docs: thermal: sync hardware protection doc with code
Date: Mon, 17 Feb 2025 21:39:43 +0100
Originally, the thermal framework's only hardware protection action was to
trigger a shutdown. This has been changed a little over a year ago to
also support rebooting as alternative hardware protection action.
Update the documentation to reflect this.
Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-3-e1c09b090c0c@xxxxxxxxxxxxxx
Fixes: 62e79e38b257 ("thermal/thermal_of: Allow rebooting after critical temp")
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Reviewed-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
Reviewed-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
Cc: Benson Leung <bleung@xxxxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Fabio Estevam <festevam@xxxxxxx>
Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>
Cc: Lukasz Luba <lukasz.luba@xxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Matteo Croce <teknoraver@xxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Rob Herring (Arm) <robh@xxxxxxxxxx>
Cc: Rui Zhang <rui.zhang@xxxxxxxxx>
Cc: Sascha Hauer <kernel@xxxxxxxxxxxxxx>
Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/driver-api/thermal/sysfs-api.rst | 25 ++++++++-------
1 file changed, 14 insertions(+), 11 deletions(-)
--- a/Documentation/driver-api/thermal/sysfs-api.rst~docs-thermal-sync-hardware-protection-doc-with-code
+++ a/Documentation/driver-api/thermal/sysfs-api.rst
@@ -413,18 +413,21 @@ This function serves as an arbitrator to
device. It sets the cooling device to the deepest cooling state if
possible.
-5. thermal_emergency_poweroff
-=============================
+5. Critical Events
+==================
-On an event of critical trip temperature crossing the thermal framework
-shuts down the system by calling hw_protection_shutdown(). The
-hw_protection_shutdown() first attempts to perform an orderly shutdown
-but accepts a delay after which it proceeds doing a forced power-off
-or as last resort an emergency_restart.
+On an event of critical trip temperature crossing, the thermal framework
+will trigger a hardware protection power-off (shutdown) or reboot,
+depending on configuration.
+
+At first, the kernel will attempt an orderly power-off or reboot, but
+accepts a delay after which it proceeds to do a forced power-off or
+reboot, respectively. If this fails, ``emergency_restart()`` is invoked
+as last resort.
The delay should be carefully profiled so as to give adequate time for
-orderly poweroff.
+orderly power-off or reboot.
-If the delay is set to 0 emergency poweroff will not be supported. So a
-carefully profiled non-zero positive value is a must for emergency
-poweroff to be triggered.
+If the delay is set to 0, the emergency action will not be supported. So a
+carefully profiled non-zero positive value is a must for the emergency
+action to be triggered.
_
Patches currently in -mm which might be from a.fatoum@xxxxxxxxxxxxxx are
reboot-replace-__hw_protection_shutdown-bool-action-parameter-with-an-enum.patch
reboot-reboot-not-shutdown-on-hw_protection_reboot-timeout.patch
docs-thermal-sync-hardware-protection-doc-with-code.patch
reboot-describe-do_kernel_restarts-cmd-argument-in-kernel-doc.patch
reboot-rename-now-misleading-__hw_protection_shutdown-symbols.patch
reboot-indicate-whether-it-is-a-hardware-protection-reboot-or-shutdown.patch
reboot-add-support-for-configuring-emergency-hardware-protection-action.patch
regulator-allow-user-configuration-of-hardware-protection-action.patch
platform-chrome-cros_ec_lpc-prepare-for-hw_protection_shutdown-removal.patch
dt-bindings-thermal-give-os-some-leeway-in-absence-of-critical-action.patch
thermal-core-allow-user-configuration-of-hardware-protection-action.patch
reboot-retire-hw_protection_reboot-and-hw_protection_shutdown-helpers.patch
