Re: Regression in v5.0-rc1 with autosuspend hrtimers

From: Tony Lindgren
Date: Wed Jan 09 2019 - 11:29:02 EST


* Rafael J. Wysocki <rafael@xxxxxxxxxx> [190109 09:44]:
> On Wed, Jan 9, 2019 at 2:51 AM Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> >
> > * Vincent Guittot <vincent.guittot@xxxxxxxxxx> [190109 01:42]:
> > > Le Tuesday 08 Jan 2019 Ã 13:37:43 (-0800), Tony Lindgren a Ãcrit :
> > > > Lowering the autosuspend_delay_ms to 2100 ms makes things work again.
> > > > Anything higher than 2200 ms seems to somehow time out immediately
> > > > now :)
> > >
> > > This is quite close to the max ns of an int on arm 32bits
> > >
> > > Could you try the patch below ?
> >
> > Yup great thanks, that's it:
> >
> > Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
>
> Cool. Thanks for getting to the bottom of this!

No problem.

One more thing I noticed: The 25% slack can get noticeable
for larger values. For things like a 3 second uart console
timeout slack of 750 ms is quite large variation.

Should we have a limit of max 100 ms for the slack?

Regards,

Tony