[PATCH v11 4/6] ARM: Exynos: switch to using generic cpufreq driver for Exynos4210/5250/5420

Viresh Kumar viresh.kumar at linaro.org
Wed Nov 19 19:48:14 PST 2014

Oh, you are still alive? I thought you were about to get married :)
Just kidding !!

On 20 November 2014 00:58, Sudeep Holla <sudeep.holla at arm.com> wrote:
> Sorry for raising this issue always with Exynos cpufreq drivers. IMO the
> bindings for "arm-bL-cpufreq-dt" is broken. Currently no one is using it
> and it's better to fix it before we have a real user of it.

Hmm, yeah if we can. I haven't found a easy way to go ahead and then
got caught in other activities.

> If you look at the binding document for it[1], it has a fixme which
> shouldn't have been there at first place. It assumes the ordering of
> CPU's specified in the DT and the logical index allocation to them.

Ok, I believe the FIXME is a bit outdated. From the code I can see only
this limitation.

- For every cluster, the cpu which boots up first should carry the OPPs.
Otherwise there is no restriction on ordering of CPUs.

- I believe CPUs boot in the order they are present in DT except for the
boot CPU. So, the first node for every cluster should have it.

Correct ? Then we can update the fixme.

> It even breaks for hotplug especially if you hotplug-in back in
> different order.

Hmm, I never thought about it. But yes the CPU with the OPPs should
be the first one to come back.

> We can work around that probably, but it's better to
> fix the binding. I failed to grab much attention in my previous attempts
> to address this[2]. Viresh also started a discussion more recently[3].

They are just stuck and went nowhere :(

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