[PATCH 1/6] arm64: dts: amlogic: Add missing cooling device properties for CPUs

Neil Armstrong narmstrong at baylibre.com
Sat May 26 01:37:49 PDT 2018


On 25/05/2018 23:10, Olof Johansson wrote:
> On Fri, May 25, 2018 at 11:10:01AM +0530, Viresh Kumar wrote:
>> The cooling device properties, like "#cooling-cells" and
>> "dynamic-power-coefficient", should either be present for all the CPUs
>> of a cluster or none. If these are present only for a subset of CPUs of
>> a cluster then things will start falling apart as soon as the CPUs are
>> brought online in a different order. For example, this will happen
>> because the operating system looks for such properties in the CPU node
>> it is trying to bring up, so that it can register a cooling device.
>> Add such missing properties.
> This seems awkward compared to just having one cooling-cells in the /cpus node
> instead.
> What's it used for? I don't see any properties in the device nodes on meson-gxm
> that have any cooling-foo cells in them? So why should #cooling-cells be
> needed?

There is no reason to have the cooling-cells on these other CPUs, the DVFS is
controlled on the first CPU of each cluster, here cpu0 and cpu4 and only
cpu0 and cpu4 are used as cooling-cells.


> -Olof
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