[PATCH v2 03/12] docs: thermal: sync hardware protection doc with code
From: Ahmad Fatoum <a.fatoum@pengutronix.de>
Date: 2025-01-13 16:26:19
Also in:
chrome-platform, linux-devicetree, linux-doc, linux-pm, lkml
Subsystem:
documentation, the rest, thermal · Maintainers:
Jonathan Corbet, Linus Torvalds, Rafael J. Wysocki, Daniel Lezcano
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.
Fixes: 62e79e38b257 ("thermal/thermal_of: Allow rebooting after critical temp")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
Documentation/driver-api/thermal/sysfs-api.rst | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
index c803b89b7248f9f26ac24608b0144db5e9c2ddb4..6b481364457b8ec56302e80bb443291c2b4a94d5 100644
--- a/Documentation/driver-api/thermal/sysfs-api.rst
+++ b/Documentation/driver-api/thermal/sysfs-api.rst@@ -413,18 +413,21 @@ This function serves as an arbitrator to set the state of a cooling 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.
--
2.39.5