CPU fequency stuck on 2600 Mhz

[PrzemyslawBanasiak13]

Dasharo version v1.0.0

Dasharo variant Protectli VP2420

Affected component(s) or functionality CPU frequency

Brief summary CPU frequency is stuck on 2600 Mhz frequency on Ubuntu 22.04

How reproducible 100%

How to reproduce

Steps to reproduce the behavior:

1. Boot the device
2. Boot to ubuntu 22.04
3. Check CPU frequency using cat /proc/cpuinfo | grep -i mhz in terminal

Expected behavior The frequency of at least one core is different than 2600 Mhz

Actual behavior CPU frequency is stuck on 2600 Mhz

[PrzemyslawBanasiak13]

Example output of cat /proc/cpuinfo | grep -i mhz command:

cpu MHz		: 2600.000
cpu MHz		: 2599.999
cpu MHz		: 2600.000
cpu MHz		: 2600.000

[miczyg1]

@PrzemyslawBanasiak13 the issue does not reproduce. On the Ubuntu that was left on eMMC I have:

cpu MHz		: 2000.000
cpu MHz		: 2000.000
cpu MHz		: 2000.000
cpu MHz		: 792.435

The frequency is jumping up and down on all cores when doing watch -n 1 "cat /proc/cpuinfo |grep -i mhz"

[miczyg1]

Also the frequency caps at 2600MHz when the CPU is being stressed with stress-ng for example which is expected behavior. I will rebuild the firmware so that it does not print coreboot debug messages on serial. Seems something is off with this binary, so will recheck on the newly built one as well

[miczyg1]

After fiing other issues and rebuilding the binary as it should be the issue is not present. Checked with DTS v1.1.0 and the cores are either at 2GHz and jumping to lower frequency.

[sulewskiprzemyslaw]

@miczyg1 @PrzemyslawBanasiak13 I just changed the labels of the issue. Currently, we are not sure whether the problem found is related to firmware, incomplete support for the processor on Ubuntu, or perhaps it is the correct idle behavior

[macpijan]

This is rather a problem regarding the test procedure using incorrect tools for the job, or the tools itself. @sulewskiprzemyslaw please update and/or close this once we have more information.

[macpijan]

@filipleple Do you have results of this on the 1.2.0?

[filipleple]

@macpijan on the 1.2.0 it doesn't get stuck on initial frequency, but then it doesn't run on expected frequency either. I've mentioned it and linked the logs in https://github.com/Dasharo/dasharo-issues/issues/763

[miczyg1]

Doing stress-ng --cpu 8 --io 4 --vm 2 --vm-bytes 128M --fork 4 --timeout 10s & on Ubuntu and then watching watch -n 1 "cat /proc/cpuinfo |grep -i mhz" returns all cores at 2600Mhz which is max for this CPU. When idling, all cores are at 800MHz, which is the lowest for this core.

All seem to be correct on v1.2.0