From a7d6ba14efb778fc8c65c627a057d5dd29debd04 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 15 Dec 2020 00:38:04 +0100 Subject: thermal/core: Remove the 'forced_passive' option The code was reorganized in 2012 with the commit 0c01ebbfd3caf1. The main change is a loop on the trip points array and a unconditional call to the throttle() ops of the governors for each of them even if the trip temperature is not reached yet. With this change, the 'forced_passive' is no longer checked in the thermal_zone_device_update() function but in the step wise governor's throttle() callback. As the force_passive does no belong to the trip point array, the thermal_zone_device_update() can not compare with the specified passive temperature, thus does not detect the passive limit has been crossed. Consequently, throttle() is never called and the 'forced_passive' branch is unreached. In addition, the default processor cooling device is not automatically bound to the thermal zone if there is not passive trip point, thus the 'forced_passive' can not operate. If there is an active trip point, then the throttle function will be called to mitigate at this temperature and the 'forced_passive' will override the mitigation of the active trip point in this case but with the default cooling device bound to the thermal zone, so usually a fan, and that is not a passive cooling effect. Given the regression exists since more than 8 years, nobody complained and at the best of my knowledge there is no bug open in https://bugzilla.kernel.org, it is reasonable to say it is unused. Remove the 'forced_passive' related code. Signed-off-by: Daniel Lezcano Reviewed-by: Thara Gopinath Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org --- Documentation/driver-api/thermal/sysfs-api.rst | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'Documentation/driver-api/thermal') diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index e7520cb439ac..a4969c474cc3 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -520,19 +520,6 @@ available_policies RW, Optional -passive - Attribute is only present for zones in which the passive cooling - policy is not supported by native thermal driver. Default is zero - and can be set to a temperature (in millidegrees) to enable a - passive trip point for the zone. Activation is done by polling with - an interval of 1 second. - - Unit: millidegrees Celsius - - Valid values: 0 (disabled) or greater than 1000 - - RW, Optional - emul_temp Interface to set the emulated temperature method in thermal zone (sensor). After setting this temperature, the thermal zone may pass -- cgit v1.2.3