Re: [Bug 55411] sysfs per-cpu cpufreq subdirs/symlinks screwed up after s2ram

Viresh Kumar
2013-03-22T13:43:33Z

Hi guys,

I will answer to questions of both of you in this mail.

On 22 March 2013 18:23, Thomas Renninger <trenn@suse.de> wrote:
> Is this all to try to fix "cpufreq driver gets loaded while some cores
> were set offline before"?

Not really. There are problems with acpi-cpufreq without that case too.

> I wonder how you run into "cpufreq is initialized with offlined cpus" case.
> I remember that there were problems, but it's nearly impossible to run
> into this if the cpufreq driver is loaded early at boot.

I always thought there is a way not to boot all cpus by passing stuff in
command line and so this is a easy case to reproduce.

> cpufreq_add_dev() and friends are complicated.

Not anymore, they are hugely simplified now.

> Those init functions got split some time ago and there also slipped
> in a bug even it was simple splitting of functions.
>
> I do not have time to look at fcf8058296edbc3de43adf095824fc32b067b9f8
> right now. Don't know how much other stuff depends on it and how
> sever it is on ARM that cpufreq does not correctly initialize with offlined
> cpus..., I would revert this patch.

Let me clear it to everybody. There isn't/shouldn't be a bug in cpufreq core,
its just that acpi-cpufreq driver isn't adapted well with the changes related to
affected_cpus and related_cpus.

I have never gone into coding for any non-ARM platform and am really not
aware of acpi-cpufreq driver and its users. That's why i told everybody where
the issue is, and they just need to fix acpi-cpufreq driver with right values of
policy->cpus (affected_cpus) and everything else would work after that.

--
viresh