Re: [PATCH v2 1/3] dt-bindings: power: limits: Describe Qualcomm SPEL hardware

From: Krzysztof Kozlowski

Date: Thu Jun 25 2026 - 02:46:06 EST


On 24/06/2026 22:41, Daniel Lezcano wrote:
> It allows power capping and read the average power consumption for a
> specific device (or/and an energy counter)
>
> Basically you can set a power constraint (power limit) to a device and
> this one won't consume more than that power (the power limitation
> strategy is managed under the hood by the firmware depending on the
> device - lower OPP, idle injection, modem weaker signal, etc ...).
>
> The RAPL or the SPEL have a hierarchical power limitation. For example:
>
> SoC
> |
> ------------------------
> | |
> Cluster0 Cluster1
> | |
> ----------------- -----------------
> | | | | | | | |
> CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
>
>
> If you specify a power limit to 'SoC', then the power consumption of
> Cluster0 + Cluster1 <= SoC
>
> If Cluster0 power consumption decreases, then Cluster1 is allowed to use
> more power until Cluster0 + Cluster1 <= SoC
>
> For me it sounds reasonable to put the device description under power/limits


Yes, can go there. Some pieces of above explanation could be captured in
commit msg.


Best regards,
Krzysztof