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Date: Mon, 26 Sep 2011 12:13:53 -0700
From: John Stultz <john.stultz@...aro.org>
To: lkml <linux-kernel@...r.kernel.org>
Cc: John Stultz <john.stultz@...aro.org>,
"Rafael J. Wysocki" <rjw@...k.pl>, arve@...roid.com,
markgross@...gnar.org, Alan Stern <stern@...land.harvard.edu>,
amit.kucheria@...aro.org, farrowg@...ibm.com,
"Dmitry Fink (Palm GBU)" <Dmitry.Fink@...m.com>,
linux-pm@...ts.linux-foundation.org, khilman@...com,
Magnus Damm <damm@...nsource.se>, mjg@...hat.com,
peterz@...radead.org
Subject: [PATCH 5/6] [RFC] alarmtimer: Add pm_stay_awake /pm_relax calls
This provides wakelock like chaining to protects the
RTC wakeup path to the hrtimer firing of the alarmtimer.
CC: Rafael J. Wysocki <rjw@...k.pl>
CC: arve@...roid.com
CC: markgross@...gnar.org
CC: Alan Stern <stern@...land.harvard.edu>
CC: amit.kucheria@...aro.org
CC: farrowg@...ibm.com
CC: Dmitry Fink (Palm GBU) <Dmitry.Fink@...m.com>
CC: linux-pm@...ts.linux-foundation.org
CC: khilman@...com
CC: Magnus Damm <damm@...nsource.se>
CC: mjg@...hat.com
CC: peterz@...radead.org
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
kernel/time/alarmtimer.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index ea5e1a9..00ee80f 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -46,12 +46,17 @@ static struct alarm_base {
static ktime_t freezer_delta;
static DEFINE_SPINLOCK(freezer_delta_lock);
+
#ifdef CONFIG_RTC_CLASS
/* rtc timer and device for setting alarm wakeups at suspend */
static struct rtc_timer rtctimer;
static struct rtc_device *rtcdev;
static DEFINE_SPINLOCK(rtcdev_lock);
+static struct wakeup_source *alarmtimer_wakelock;
+static int stay_awake;
+static DEFINE_SPINLOCK(stay_awake_lock);
+
/**
* has_wakealarm - check rtc device has wakealarm ability
* @dev: current device
@@ -73,6 +78,19 @@ static int has_wakealarm(struct device *dev, void *name_ptr)
return 1;
}
+/* rtctimer function called by first rtc interrupt after suspend */
+void alarmtimer_resume_call(void* p)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&stay_awake_lock, flags);
+ if (stay_awake == 1) {
+ stay_awake = 2;
+ __pm_stay_awake(alarmtimer_wakelock);
+ }
+ spin_unlock_irqrestore(&stay_awake_lock, flags);
+}
+
/**
* alarmtimer_get_rtcdev - Return selected rtcdevice
*
@@ -99,7 +117,7 @@ static struct rtc_device *alarmtimer_get_rtcdev(void)
* rtc_open takes its own.
*/
put_device(dev);
- rtc_timer_init(&rtctimer, NULL, NULL);
+ rtc_timer_init(&rtctimer, alarmtimer_resume_call, NULL);
}
}
ret = rtcdev;
@@ -158,6 +176,8 @@ static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm)
}
+
+
/**
* alarmtimer_fired - Handles alarm hrtimer being fired.
* @timer: pointer to hrtimer being run
@@ -175,6 +195,8 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
ktime_t now;
int ret = HRTIMER_NORESTART;
+
+ __pm_stay_awake(alarmtimer_wakelock);
spin_lock_irqsave(&base->lock, flags);
now = base->gettime();
while ((next = timerqueue_getnext(&base->timerqueue))) {
@@ -206,6 +228,13 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
}
spin_unlock_irqrestore(&base->lock, flags);
+ spin_lock_irqsave(&stay_awake_lock, flags);
+ if (stay_awake == 2)
+ __pm_relax(alarmtimer_wakelock);
+ stay_awake = 0;
+ spin_unlock_irqrestore(&stay_awake_lock, flags);
+ __pm_relax(alarmtimer_wakelock);
+
return ret;
}
@@ -225,12 +254,14 @@ static int alarmtimer_suspend(struct device *dev)
{
struct rtc_time tm;
ktime_t min, now;
+ int min_base;
unsigned long flags;
struct rtc_device *rtc;
int i;
spin_lock_irqsave(&freezer_delta_lock, flags);
min = freezer_delta;
+ min_base = 0;
freezer_delta = ktime_set(0, 0);
spin_unlock_irqrestore(&freezer_delta_lock, flags);
@@ -251,8 +282,10 @@ static int alarmtimer_suspend(struct device *dev)
if (!next)
continue;
delta = ktime_sub(next->expires, base->gettime());
- if (!min.tv64 || (delta.tv64 < min.tv64))
+ if (!min.tv64 || (delta.tv64 < min.tv64)) {
min = delta;
+ min_base = i;
+ }
}
if (min.tv64 == 0)
return 0;
@@ -266,6 +299,10 @@ static int alarmtimer_suspend(struct device *dev)
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);
+ spin_lock_irqsave(&stay_awake_lock, flags);
+ stay_awake=1;
+ spin_unlock_irqrestore(&stay_awake_lock, flags);
+
rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
return 0;
@@ -703,6 +740,9 @@ static int __init alarmtimer_init(void)
.nsleep = alarm_timer_nsleep,
};
+ alarmtimer_wakelock = wakeup_source_register("alarmtimer");
+ stay_awake=0;
+
posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
--
1.7.3.2.146.gca209
--
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