Re: [PATCH v2 1/2] devfreq: qcom: Add L2 Krait Cache devfreq scaling driver

[Sudeep Holla]

On Tue, Sep 29, 2020 at 06:29:24PM +0200, Ansuel Smith wrote:
> Qcom L2 Krait CPUs use the generic cpufreq-dt driver and doesn't actually
> scale the Cache frequency when the CPU frequency is changed. This
> devfreq driver register with the cpu notifier and scale the Cache
> based on the max Freq across all core as the CPU cache is shared across
> all of them. If provided this also scale the voltage of the regulator
> attached to the CPU cache. The scaling logic is based on the CPU freq
> and the 3 scaling interval are set by the device dts.
>

I have raised this concern before. I am worried this kind of independent
CPU and cache frequency controls make way for clkscrew kind of attacks.
Why can't the clocks be made parent/child or secondary and automatically
updated when CPU clocks are changed.

-- 
Regards,
Sudeep