Re: Fail to enter retention

[Tony Lindgren <tony@atomide.com>]

* Ran Shalit <ranshalit@gmail.com> [141118 00:26]:
> 
> In coninuity to my previous message, thse is the log for time in state
> 0-state 6:
> 
> On Tue, Nov 18, 2014 at 10:21 AM, Ran Shalit <ranshalit@gmail.com> wrote:
> >
> > When I try to do suspend from userspace, I get better results and it
> > seems that all domain been put to RET or OFF but on checking power
> > state time it still shows 0. Do you know why ?

Looks like you still have some hardware blocking off states. Maybe the
state time shows only that?

> >> Probably a dumb question... But if I try to print them won't it
> >> automatically wakes up the serial (by the way should the serial wakeup
> >> be configured to RX pin only ?)

Yes for the RX pin only as that's where the wake-up event comes from.

> >> Another thing I don't understand... Can it be that there is some
> >> ongoing kernel process that also prevent me for entering retention ?

Could be if you have something CPU intensive going on like tracing.

> >> I think maybe I should try first to suspend (instead of trying to
> >> enter retention in idle) , maybe it might bring better result ?

Yes from the hardware point of view suspend does the same thing as
the deeper idle states.

Regards,

Tony