[PATCH 13/25] OMAP4: PM: Add WakeupGen module as OMAP gic_arch_extn

On Thursday 15 September 2011 12:34 AM, Tony Lindgren wrote:

* Santosh [off-list ref] [110914 09:49]:

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On Wednesday 14 September 2011 10:48 PM, Tony Lindgren wrote:

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* Santosh[off-list ref]  [110914 09:40]:

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On Wednesday 14 September 2011 10:38 PM, Tony Lindgren wrote:

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* Santosh[off-list ref]   [110914 09:16]:

Thanks for the clarification. It seems to me the spec is most likely
wrong as we've had the GIC working for over two years now without
doing anything with the wakeup gen registers :)

It's working because CPU clockdomain are never put under HW
supervised mode and they are kept in force wakeup. Clock-domain
never idles on mainline code. PM series will put the clock-domains
under HW supervison as needed to achieve any low power states and
then all sorts of corner cases will come out.

But again the wakeup gen triggers only do something when hitting
idle. There should be no use for them during runtime, right?

You missed my point in the description. Clockdomain inactive
doesn't depend on idle or WFI execution. Under HW supervison
CPU clock domain can get into inactive when CPU is stalled and
waiting for a read response from slow interconnect.

Ah OK. If it's needed during runtime too then that explains why
the registers need to be kept in sync.

quoted

One thing for sure. Designers has chosen a wrong name to this
IP. Wakeugen apears like needed only for low power wakeup which
not seems to be entirely correct as per specs

Yes it's not obvious reading the TRM either. Maybe add some
comment about that to the patch?

You are right. Documentation isn't clear about this. Will
add the above point in change log.

btw, thanks for the good discussion on this topic.

Regards
Santosh