Re: [PATCH v4] ARM: perf: save/restore pmu registers in pm notifier

From: Will Deacon
Date: Mon Oct 20 2014 - 05:20:26 EST


On Mon, Oct 20, 2014 at 10:16:16AM +0100, Sudeep Holla wrote:
> On 20/10/14 09:46, Neil Zhang wrote:
> > Will, I prefer to check always-on field under PMU node to check
> > whether we need Save/restore them.
> >
> But how do you handle it for different idle states. e.g. if CPU is in
> retention, PMU's *might be* retained. Also I don't think PMUs will be
> placed in "always-on" power domain like timers. So using "always-on"
> sounds incorrect to me.

Adding Mathieu to CC, since I spoke to him at LPC about this and he was
talking about implementing proper PM domain descriptions for coresight
components.

Will
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