[lkml]   [2020]   [Sep]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 1/2] devfreq: qcom: Add L2 Krait Cache devfreq scaling driver
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.


 \ /
  Last update: 2020-09-30 11:32    [W:0.050 / U:2.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site