Hello Jouni, 

On Tue, 12 Aug 2008, Högander Jouni wrote:

> "ext Paul Walmsley" <[EMAIL PROTECTED]> writes:
> 
> > On Mon, 11 Aug 2008, Högander Jouni wrote:
> >
> >> "ext Paul Walmsley" <[EMAIL PROTECTED]> writes:
> >>
> >> > Could you explain a little further why PER would have a wakeup 
> >> > dependency 
> >> > on CORE?  Is this something that we should only enable under certain 
> >> > conditions, e.g., latency requirements for a device in PER?
> >> 
> >> This is done to make sure we don't loose any gpio interrupts: GPIO
> >> wakeup/interrupt doesn't work for GPIOs in PER domain if PER is not
> >> active.
> >
> > I'm probably misunderstanding something, but ... wouldn't it better to 
> > just keep PER powerdomain ON all the time when PER GPIOs are enabled for 
> > interrupts?  It seems possible for PER to go to retention or OFF even with 
> > the CORE wkdep in place, which would result in a period of time where the 
> > interrupts would be missed, no?
> 
> No, it won't, PER goes sleep state only if CORE goes
> too. There is a hardware sleepdep between PER and CORE, thanks to
> Rajendra for pointing this out some time ago. This way there are all
> the time some wakeup mechanism available for PER gpios
> (gpio/iopad). Leaving PER ON would increase consumption.

Ah, I see.

Do you think we should add a mechanism for the CORE->PER wkdep to be 
dynamically added and removed, based on whether GPIO2-6 balls are enabled 
in IO pad wakeup?  Conceivably a board could just use GPIO1 (in WKUP), and 
PER would not need to be awakened along with CORE in those instances, 
correct?


- Paul

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