linux-kernel - Re: [PATCH 3/3] PM / Sleep: Make __pm_stay

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Message-ID: <CAMP5Xgctu7ra6XbgNuTo5uP77otboXmSxAaLHj1uJwiH1+ce9g@mail.gmail.com>
Date:	Wed, 15 Feb 2012 20:55:54 -0800
From:	Arve Hjønnevåg <arve@...roid.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Linux PM list <linux-pm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] PM / Sleep: Make __pm_stay_awake() delete wakeup
 source timers

2012/2/15 Rafael J. Wysocki <rjw@...k.pl>:
...
> --- linux.orig/drivers/base/power/wakeup.c
> +++ linux/drivers/base/power/wakeup.c
> @@ -365,9 +365,15 @@ void __pm_stay_awake(struct wakeup_sourc
>                return;
>
>        spin_lock_irqsave(&ws->lock, flags);
> +
> +       del_timer(&ws->timer);
> +       ws->timer_expires = 0;

timer_expires gets overwritten in wakeup_source_activate, so
__pm_relax followed by __pm_stay_awake is still not safe.



...
> @@ -529,8 +535,12 @@ void __pm_wakeup_event(struct wakeup_sou
>        spin_lock_irqsave(&ws->lock, flags);
>
>        ws->event_count++;
> -       if (!ws->active)
> +       if (ws->active) {
> +               if (!ws->timer_expires)
> +                       goto unlock;
> +       } else {
>                wakeup_source_activate(ws);
> +       }
>
>        if (!msec) {
>                wakeup_source_deactivate(ws);
>

I suggest dropping this and adding:

-       if (time_after(expires, ws->timer_expires)) {
+       if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {



-- 
Arve Hjønnevåg
--
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