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a7d6ba14ef
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 <daniel.lezcano@linaro.org> Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org> Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org
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.