rtc: Disable the alarm in the hardware (v2)

BugLink: http://bugs.launchpad.net/bugs/971808

commit 41c7f7424259ff11009449f87c95656f69f9b186 upstream.

Currently, the RTC code does not disable the alarm in the hardware.

This means that after a sequence such as the one below (the files are in the
RTC sysfs), the box will boot up after 2 minutes even though we've
asked for the alarm to be turned off.

	# echo $((`cat since_epoch`)+120) > wakealarm
	# echo 0 > wakealarm
	# poweroff

Fix this by disabling the alarm when there are no timers to run.

The original version of this patch was reverted. This version
disables the irq directly instead of setting a disabled timer
in the future.

Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
[Merged in the second revision from Rabin]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 38d1dc74b2c..636a2ec2181 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -762,6 +762,14 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
         return 0;
 }
 
+static void rtc_alarm_disable(struct rtc_device *rtc)
+{
+        if (!rtc->ops || !rtc->ops->alarm_irq_enable)
+                return;
+
+        rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
+}
+
 /**
  * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
  * @rtc rtc device
@@ -783,8 +791,10 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
                 struct rtc_wkalrm alarm;
                 int err;
                 next = timerqueue_getnext(&rtc->timerqueue);
-                if (!next)
+                if (!next) {
+                        rtc_alarm_disable(rtc);
                         return;
+                }
                 alarm.time = rtc_ktime_to_tm(next->expires);
                 alarm.enabled = 1;
                 err = __rtc_set_alarm(rtc, &alarm);
@@ -846,7 +856,8 @@ again:
                 err = __rtc_set_alarm(rtc, &alarm);
                 if (err == -ETIME)
                         goto again;
-        }
+        } else
+                rtc_alarm_disable(rtc);
 
         mutex_unlock(&rtc->ops_lock);
 }