mvebu: armada 3720 cpufreq reverts

Marek Behún marek.behun at
Wed Jun 30 06:19:41 PDT 2021

Hello Robert,

I am writing regarding commit
  mvebu: 5.10 fix DVFS caused random boot crashes;a=commit;h=080a0b74e39d159eecf69c468debec42f28bf4d8
in OpenWRT.

This commit reverts the one patch of a3720 cpufreq driver, but not
the subsequent ones.

Your commit message says that some 1.2 GHz SOCs are unstable with the
fix. Did you also test this with the subsequent patches, which are now
in stable kernels? I guess the answer is yes, because all these patches
were backported to 5.10.37.

I am of the opinion that a better approach would be to
- either disable cpufreq for 1.2 GHz variants
- fix a3720 cpufreq driver to only scale up to 1 GHz on 1.2 GHz variant

Since the approach you've taken now (reverting the patch) basically
changes the CPU parnet clock to DDR clock, which is just wrong.
Worse is that you are doing this for everybody, not just for the 1.2
GHz variants.

What do you think?


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