[PATCH 1/2] rtc-cmos: Clear expired alarm after resume

[Gabriele Mazzotta]

If the system wakes up because of a wake alarm, the internal state
of the alarm is not updated. As consequence, the state no longer
reflects the actual state of the hardware and setting a new alarm
is not possible until the expired alarm is cleared.

Signed-off-by: Gabriele Mazzotta <gabriele....@gmail.com>
---
 drivers/rtc/rtc-cmos.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index fbe9c72..fd121e3 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -900,11 +900,33 @@ static inline int cmos_poweroff(struct device *dev)
 
 #ifdef CONFIG_PM_SLEEP
 
+static void cmos_check_alarm(struct device *dev)
+{
+       struct cmos_rtc *cmos = dev_get_drvdata(dev);
+       struct rtc_wkalrm alarm;
+       struct rtc_time now;
+       time64_t t_now;
+       time64_t t_expires;
+
+       cmos_read_time(dev, &now);
+       rtc_read_alarm(cmos->rtc, &alarm);
+       t_now = rtc_tm_to_time64(&now);
+       t_expires = rtc_tm_to_time64(&alarm.time);
+
+       if (t_expires <= t_now && alarm.enabled) {
+               alarm.enabled = 0;
+               cmos->suspend_ctrl &= ~RTC_AIE;
+               rtc_set_alarm(cmos->rtc, &alarm);
+       }
+}
+
 static int cmos_resume(struct device *dev)
 {
        struct cmos_rtc *cmos = dev_get_drvdata(dev);
        unsigned char tmp;
 
+       cmos_check_alarm(dev);
+
        if (cmos->enabled_wake) {
                if (cmos->wake_off)
                        cmos->wake_off(dev);
-- 
2.8.1