Re: [PATCH 1/2] PM / wakeup: Remove timer from wakeup_source_remove()

Viresh Kumar
2019-03-12T03:28:12Z

On 11-03-19, 13:05, Rafael J. Wysocki wrote:
> On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote:
> > wakeup_source_remove() is the counterpart of wakeup_source_add() helper
> > and must undo the initializations done by wakeup_source_add(). Currently
> > the timer is initialized by wakeup_source_add() but removed from
> > wakeup_source_drop(), which doesn't look logically correct. Also it
> > should be okay to call wakeup_source_add() right after calling
> > wakeup_source_remove(), and in that case we may end up calling
> > timer_setup() for a potentially scheduled timer which is surely
> > incorrect.
> >
> > Move the timer removal part to wakeup_source_remove() instead.
> >
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> > drivers/base/power/wakeup.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> > index f1fee72ed970..18333962e3da 100644
> > --- a/drivers/base/power/wakeup.c
> > +++ b/drivers/base/power/wakeup.c
> > @@ -118,7 +118,6 @@ void wakeup_source_drop(struct wakeup_source *ws)
> > if (!ws)
> > return;
> >
> > - del_timer_sync(&ws->timer);
> > __pm_relax(ws);
> > }
> > EXPORT_SYMBOL_GPL(wakeup_source_drop);
> > @@ -205,6 +204,8 @@ void wakeup_source_remove(struct wakeup_source *ws)
> > list_del_rcu(&ws->entry);
> > raw_spin_unlock_irqrestore(&events_lock, flags);
> > synchronize_srcu(&wakeup_srcu);
> > +
> > + del_timer_sync(&ws->timer);
> > }
> > EXPORT_SYMBOL_GPL(wakeup_source_remove);
> >
> >
>
> I've merged it with the [2/2], rewritten the subject and changelog and
> queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup
> source timer cancellation").

Okay, thanks. We (Android guys) want this to be backported into 4.4+
kernels via the stable tree. Can we mark this for stable in the commit
itself ? Else I would be required to send this separately for all the
kernels. I should have marked it for stable initially though, sorry
about forgetting then.

--
viresh