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

From: Tony Lindgren
Date: Tue Jan 08 2019 - 16:37:48 EST


* Vincent Guittot <vincent.guittot@xxxxxxxxxx> [190108 16:42]:
> On Tue, 8 Jan 2019 at 16:53, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> > Hmm so could it be that we now rely on timers that that may
> > not be capable of waking up the system from idle states with
> > hrtimer?
>
> With nohz and hrtimer enabled, timer relies on hrtimer to generate
> the tick so you should use the same interrupt.

OK yeah looks like that part is working just fine.

Adding some printks and debugging over ssh, looks like
omap8250_runtime_resume() gets called just fine based on a wakeirq,
but then omap8250_runtime_suspend() runs immediately instead of
waiting for the three second timeout.

Lowering the autosuspend_delay_ms to 2100 ms makes things work again.
Anything higher than 2200 ms seems to somehow time out immediately
now :)

Regards,

Tony