Re: Governor problem with generic 6.1 arm64 kernel on Raspberry

[Alex <sokoloff@e-mail.de>]

I have to admit that I drew the wrong conclusions. Some of my frequency readings were conducted within an x-terminal, some on a console screen, without X running. That, in fact, seemed to make the difference.

Booting in any of the 6.1 upstream generic kernels works fine, including the governor, as long as I remained in text mode. Also switching between different governors immediately brought the intended result. 

Once starting the X Server (X.Org 1.20.11 with either fbdev or fbturbo driver) causes the CPU frequency not following the scaling frequency any more but stick to the maximum speed defined as per firmware or config.txt. Shutting down the X server does not revert this.

For me this seems to be a gpu related issue ... ?

Regards,

Alex

On Wed, 2024-03-13 at 14:27 +0100, Alex wrote:

There was a typo in my last statement...

oldstable 5.10 --> governor *is* working

oldstable 6.1 backport --> governor not working

oldstable 6.1 RT backport --> governor is working

stable 6.1 --> governor is working

On Wed, 2024-03-13 at 13:41 +0100, Alex wrote:

Hi Andy,

I see your point... however the governor working or not seems to be a

pure kernel issue, and Devuan does not support any arm platform and

not build the generic kernels in the apt repository. Their repository

is mainly fed from Debian one, with some changes when it comes to

systemd vs. init.

There are prebuilt images for arm64 with custom compiled kernels

without any method to do regular updates (they do not feed these

kernels to the apt repository). This is why I ended in compiling the

kernel by myself in the first place. 

However, to be sure it really is a kernel issue I gave

20231109_raspi_4_bookworm.img an try today and the governor worked.

So I installed the 6.1 kernel from the stable repository on my

oldstable Devuan userland and still, the governor works.

So, there seems to be a difference between the 6.1 oldstable backport

kernels vs. the ones in the stable repository.

My first posts primary intention was not to get support (as I do have

a running system), but to point out a possible bug which is present

in some Debian arm64 kernels, while others are working fine.

oldstable 5.10 --> governor not working

oldstable 6.1 backport --> governor not working

oldstable 6.1 RT backport --> governor working

stable 6.1 --> governor working

So after all, this does not seem to be a Devuan issue. I'd be glad to

help tracking down this issue.

Alex

On Tue, 2024-03-12 at 22:26 +0000, Andrew M.A. Cater wrote:

On Tue, Mar 12, 2024 at 11:14:10AM +0100, Alex wrote:

Hi there,

I am running a Raspberry Pi 4 with an oldstable release for a few

years

now. In fact, it is Devuan Chimaera, corresponding to Debian 11

Bookworm without systemd. As the kernel images comes straight

from

Debian, I am reporting it here...

Can I respectfully suggest that you ask Devuan for help?

if you use the images at raspi.debian.net, we may be able to help

you.

If you want to try booting using UEFI and a stock Debian image, we

can also offer advice.

For Devuan - we cannot be entirely sure that the advice we give

will

be correct.

With every good wish, as ever,

Andy

Alex