diff options
| author | Zoran Markovic <zoran.markovic@linaro.org> | 2013-06-26 16:09:13 -0700 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2013-07-22 09:38:25 -0700 |
| commit | 14d0e347ea2db51144a8800d7c7576db96f69983 (patch) | |
| tree | fd56f98424f8f9517ba6be8f8de4fb67147fe828 | |
| parent | 07862c1cd6675cde2dd4bd64e64d704ea2185b79 (diff) | |
| download | linux-14d0e347ea2db51144a8800d7c7576db96f69983.tar.bz2 | |
rtc: Keep system awake until all expired RTC timers are handled
Current implementation of RTC interface allows for system suspend to
occur in the following cases:
(a) if a timer is set in the past and rtc_timer_do_work() is scheduled
to handle it, and
(b) if rtc_timer_do_work() is called to handle expired timers whose
handlers implement a preemption point.
A pending suspend request may be honoured in the above cases causing
timer handling to be delayed until after the next resume. This is
undesirable since timer handlers may have time-critical code to execute.
This patch makes sure that the system stays awake until all expired
timers are handled.
Note that all calls to pm_stay_awake() are eventually paired with
the single pm_relax() call in rtc_timer_do_work(), which is launched
using schedule_work().
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Arve Hjonnevag <arve@android.com>
Cc: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
| -rw-r--r-- | drivers/rtc/interface.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 72c5cdbe0791..544be722937c 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -72,6 +72,7 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) } else err = -EINVAL; + pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); /* A timer might have just expired */ schedule_work(&rtc->irqwork); @@ -113,6 +114,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) err = -EINVAL; } + pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); /* A timer might have just expired */ schedule_work(&rtc->irqwork); @@ -771,9 +773,10 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) alarm.time = rtc_ktime_to_tm(timer->node.expires); alarm.enabled = 1; err = __rtc_set_alarm(rtc, &alarm); - if (err == -ETIME) + if (err == -ETIME) { + pm_stay_awake(rtc->dev.parent); schedule_work(&rtc->irqwork); - else if (err) { + } else if (err) { timerqueue_del(&rtc->timerqueue, &timer->node); timer->enabled = 0; return err; @@ -818,8 +821,10 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) alarm.time = rtc_ktime_to_tm(next->expires); alarm.enabled = 1; err = __rtc_set_alarm(rtc, &alarm); - if (err == -ETIME) + if (err == -ETIME) { + pm_stay_awake(rtc->dev.parent); schedule_work(&rtc->irqwork); + } } } @@ -845,7 +850,6 @@ void rtc_timer_do_work(struct work_struct *work) mutex_lock(&rtc->ops_lock); again: - pm_relax(rtc->dev.parent); __rtc_read_time(rtc, &tm); now = rtc_tm_to_ktime(tm); while ((next = timerqueue_getnext(&rtc->timerqueue))) { @@ -880,6 +884,7 @@ again: } else rtc_alarm_disable(rtc); + pm_relax(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); } |