cpufreq(-dt) with two clocks but one regulator

Heiko Stuebner heiko at sntech.de
Thu Sep 14 15:53:42 PDT 2017

Hi Viresh,

if possible I'd like a pointer in the right direction for the following

The rk3368 has two cpu clusters of 4 Cortex-A53 cores each, with separate
clock supplies but sharing its supplying regulator. It looks like it was
originally meant for some switched big-little system, with the little
cluster maxing out at 1.2GHz while the big cluster can reach 1.5GHz.

This of course fails miserably with current cpufreq, as the two sets
of operating points fight over control of the regulator and after talking
with real-life users of the soc it seems most desireable to have all
8 cores available at 1.2GHz than only 4 at 1.5GHz max.

But as the clock seems to be bound to the opp table itself simply sharing
the table of course also doesn't work, as only the first clock would be set.

I'm currently only seeing somehow hacky options to solve this, so if you
have some direction on how to solve something like this I would be really
grateful :-)


More information about the Linux-rockchip mailing list