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

bugzilla-daemon
2013-03-25T11:15:45Z

--- Comment #37 from Duncan <1i5t5.duncan@cox.net> 2013-03-25 11:15:44 ---
On Sun, 24 Mar 2013 17:53:41 +0530
Viresh Kumar <viresh.kumar@linaro.org> wrote:

> On 24 March 2013 17:46, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > Fixing Duncan's issues shouldn't be a very big deal now as i was
> > thinking too much about what was broken without my patches too. And
> > now that part is pretty clear.
>
> Hi Duncan,
>
> Try attached patch and this should take back your system to where it
> was.
>
> NOTE: With this patch your related_cpus wouldn't show any groups and
> related cpus must be same as affected cpus. All cpu*/cpufreq must be
> directories now and no symlinks.

FWIW, with this patch, pre-s2ram and post-resume are indeed consistent,
but it's not back to where it was.

With this patch, each core is a cpufreq law unto itself. Maybe that's
what you meant with the note, maybe not (I know the mapping of sysfs
files to cpufreq-info output was stated up-thread, but I lost track,
and how affected vs related maps to hardware vs software coordinated
and what it all actually means other than what I'm seeing isn't ideal,
is apparently a bit more than I'm able to keep in my head ATM), but it's
what I get. The relevant bits of cpufreq-info output:

analyzing CPU 0:
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
analyzing CPU 1:
CPUs which run at the same hardware frequency: 1
CPUs which need to have their frequency coordinated by software: 1
analyzing CPU 2:
CPUs which run at the same hardware frequency: 2
CPUs which need to have their frequency coordinated by software: 2
analyzing CPU 3:
CPUs which run at the same hardware frequency: 3
CPUs which need to have their frequency coordinated by software: 3
analyzing CPU 4:
CPUs which run at the same hardware frequency: 4
CPUs which need to have their frequency coordinated by software: 4
analyzing CPU 5:
CPUs which run at the same hardware frequency: 5
CPUs which need to have their frequency coordinated by software: 5

But at least it's consistent: The same results both before and after a
suspend/resume cycle.

And given that 3.8 wasn't ideal either, maybe that's good enough for
this cycle, and a real fix will have to wait until the next commit
window and stable-tree. That'd give us more leeway to fix it right, as
well as a full cycle for testing anything else the "correct" fix might
dredge up.