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

Vincent Guittot
2019-01-09T01:42:18Z

Le Tuesday 08 Jan 2019 à 13:37:43 (-0800), Tony Lindgren a écrit :
> * Vincent Guittot <vincent.guittot@linaro.org> [190108 16:42]:
> > On Tue, 8 Jan 2019 at 16:53, Tony Lindgren <tony@atomide.com> 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 :)

This is quite close to the max ns of an int on arm 32bits

Could you try the patch below ?

---
drivers/base/power/runtime.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 7062469..44c5c76 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -141,7 +141,7 @@ u64 pm_runtime_autosuspend_expiration(struct device *dev)

last_busy = READ_ONCE(dev->power.last_busy);

- expires = last_busy + autosuspend_delay * NSEC_PER_MSEC;
+ expires = last_busy + (u64)(autosuspend_delay) * NSEC_PER_MSEC;
if (expires <= now)
expires = 0; /* Already expired. */

--
2.7.4

>
> Regards,
>
> Tony