<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/thermal/gov_step_wise.c, branch v5.19-rc3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>thermal/core: Remove the 'forced_passive' option</title>
<updated>2021-01-19T21:22:45+00:00</updated>
<author>
<name>Daniel Lezcano</name>
<email>daniel.lezcano@linaro.org</email>
</author>
<published>2020-12-14T23:38:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a7d6ba14efb778fc8c65c627a057d5dd29debd04'/>
<id>a7d6ba14efb778fc8c65c627a057d5dd29debd04</id>
<content type='text'>
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 &lt;daniel.lezcano@linaro.org&gt;
Reviewed-by: Thara Gopinath &lt;thara.gopinath@linaro.org&gt;
Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;daniel.lezcano@linaro.org&gt;
Reviewed-by: Thara Gopinath &lt;thara.gopinath@linaro.org&gt;
Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org
</pre>
</div>
</content>
</entry>
<entry>
<title>thermal/governors: Prefix all source files with gov_</title>
<updated>2020-05-22T16:48:54+00:00</updated>
<author>
<name>Amit Kucheria</name>
<email>amit.kucheria@linaro.org</email>
</author>
<published>2020-05-11T12:25:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0015d9a2a72745308ef9728a746ff7b1e82138bc'/>
<id>0015d9a2a72745308ef9728a746ff7b1e82138bc</id>
<content type='text'>
Bang-bang governor source file is prefixed with gov_. Do the same for
other governors for consistency so they're easy to find in the sources.

Signed-off-by: Amit Kucheria &lt;amit.kucheria@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Link: https://lore.kernel.org/r/b9a85d3204712f14e320504948c12712dc0b291b.1589199124.git.amit.kucheria@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Bang-bang governor source file is prefixed with gov_. Do the same for
other governors for consistency so they're easy to find in the sources.

Signed-off-by: Amit Kucheria &lt;amit.kucheria@linaro.org&gt;
Signed-off-by: Daniel Lezcano &lt;daniel.lezcano@linaro.org&gt;
Link: https://lore.kernel.org/r/b9a85d3204712f14e320504948c12712dc0b291b.1589199124.git.amit.kucheria@linaro.org
</pre>
</div>
</content>
</entry>
</feed>
