From 14d0e347ea2db51144a8800d7c7576db96f69983 Mon Sep 17 00:00:00 2001 From: Zoran Markovic Date: Wed, 26 Jun 2013 16:09:13 -0700 Subject: 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 Cc: John Stultz Cc: Arve Hjonnevag Cc: Todd Poynor Signed-off-by: Zoran Markovic Signed-off-by: John Stultz --- drivers/rtc/interface.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/rtc') 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); } -- cgit v1.2.3 From 07783397c6e3757de805bda5e1139a9e47aa7d74 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 17 Sep 2013 11:20:21 -0700 Subject: rtc: rtc-pl031: Set wakeup flag prior to registering rtcdev In some recent testing, I noticed the CLOCK_REALTIME_ALARM clockid wasn't functioning on my vexpress qemu environment. Looking into it I noticed the pl031 rtc driver doesn't set the wakeup flag on the device until after registering the device with the RTC subsystem. This causes the alarmtimer subsystem to not see the pl031 driver as a valid backing device, and that resuls in alarm clockids getting ENOTSUPP errors. Thus be sure to set the wakeup flag on the device prior to registering the rtcdev so the pl031 rtc driver can be used as the backing alarmtimer device. Cc: Linus Walleij Cc: Alessandro Zummo Cc: "Jon Medhurst (Tixy)" Cc: linux-arm-kernel@lists.infradead.org Acked-by: Linus Walleij Signed-off-by: John Stultz --- drivers/rtc/rtc-pl031.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c index 0f0609b1aa2c..e3b25712b659 100644 --- a/drivers/rtc/rtc-pl031.c +++ b/drivers/rtc/rtc-pl031.c @@ -371,6 +371,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id) } } + device_init_wakeup(&adev->dev, 1); ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, THIS_MODULE); if (IS_ERR(ldata->rtc)) { @@ -384,8 +385,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id) goto out_no_irq; } - device_init_wakeup(&adev->dev, 1); - return 0; out_no_irq: -- cgit v1.2.3