Re: [PATCH 0/4] ARM: da850: enable cpufreq in DT mode

From: David Lechner
Date: Thu Mar 21 2019 - 11:29:28 EST


On 3/21/19 9:10 AM, Bartosz Golaszewski wrote:
From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

This series adds cpufreq-dt operating points for da850 boards supported
with device tree (da850-lcdk, da850-lego-ev3, da850-evm) and also
includes a fix for the da850-evm boardfile which checks an unset variable
to determine the highest available frequency for cpufreq.


I can't find any old threads about this, but I recall that there was a
problem with the USB OHCI controller breaking when switching frequencies.
It didn't happen all of the time, but often enough that it made using
cpufreq unusable for me. Is this still a problem?

Also, a big-picture question. On boards with fixed regulators, what is
the benefit of enabling frequency scaling? The power savings aspect
seems negligible (< 1% in my tests) since the voltage cannot be changed.