rtc: set the alarm to the next expiring timer

commit 74717b28cb32e1ad3c1042cafd76b264c8c0f68d upstream.

If there is any non expired timer in the queue, the RTC alarm is never set.
This is an issue when adding a timer that expires before the next non
expired timer.

Ensure the RTC alarm is set in that case.

Fixes: 2b2f5ff00f63 ("rtc: interface: ignore expired timers when enqueuing new timers")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
[bwh: Backported to 3.2: open-code ktime_before()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index a623983b87168fbe97e973186a4e8515a5cae53c..3b58f94be227309bb88301cf5de5031af90c69b1 100644 (file)
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -765,7 +765,7 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
        }
 
        timerqueue_add(&rtc->timerqueue, &timer->node);
-       if (!next) {
+       if (!next || timer->node.expires.tv64 < next->expires.tv64) {
                struct rtc_wkalrm alarm;
                int err;
                alarm.time = rtc_ktime_to_tm(timer->node.expires);