[PATCH] drivers: rtc: handle OTF clock changes

[Elad Nachman]

From: Elad Nachman <enachman@xxxxxxxxxxx>

When processing expired RTC events and rearming them, use now
instead of expiry to prevent endless loops.
Issue seen with Armada 385 SOC.

Fixes commit 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events")
Signed-off-by: Elad Nachman <enachman@xxxxxxxxxxx>
---
 drivers/rtc/interface.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 96626f8068f9..c32ef95a07d4 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -126,6 +126,7 @@ EXPORT_SYMBOL_GPL(rtc_read_time);
 int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 {
 	int err, uie;
+	struct rtc_time new_tm;
 
 	err = rtc_valid_tm(tm);
 	if (err != 0)
@@ -159,6 +160,17 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 	else
 		err = -EINVAL;
 
+	if (rtc && rtc->ops && rtc->ops->read_time) {
+		if (!rtc->ops->read_time(rtc->dev.parent, &new_tm)) {
+			pr_debug("new rtc time secs %d mins %d hours %d mday %d mon %d year %d way %d yday %d dst %d\n",
+					new_tm.tm_sec, new_tm.tm_min,
+					new_tm.tm_hour, new_tm.tm_mday,
+					new_tm.tm_mon, new_tm.tm_year,
+					new_tm.tm_wday, new_tm.tm_yday,
+					new_tm.tm_isdst);
+		}
+	}
+
 	pm_stay_awake(rtc->dev.parent);
 	mutex_unlock(&rtc->ops_lock);
 	/* A timer might have just expired */
@@ -999,7 +1011,7 @@ void rtc_timer_do_work(struct work_struct *work)
 		trace_rtc_timer_fired(timer);
 		/* Re-add/fwd periodic timers */
 		if (ktime_to_ns(timer->period)) {
-			timer->node.expires = ktime_add(timer->node.expires,
+			timer->node.expires = ktime_add(now,
 							timer->period);
 			timer->enabled = 1;
 			timerqueue_add(&rtc->timerqueue, &timer->node);
-- 
2.25.1