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Subject[PATCH] alarmtimer: Add the verification code for rtc device error.
In alarmtimer_suspend(), the error after rtc_read_time() is not checked.
If rtc device fail to read rtc time, we cannot ensure the following process.

Furthermore, the return value of rtc_timer_start() needs to distinguish
-ETIME and other rtc device error. If the error is relevant to rtc device,
suspend is failed unintentionally. In this case, it just returns zero for
a stable suspend. Otherwise, in the worst case, suspend will fail continually.

So, this patch verifies the rtc device error in alarmtimer_suspend(). it
includes "rtc_err goto" statement instead of a direct "return 0" to clarify
the rtc device error.

Signed-off-by: Hyogi Gim <>
kernel/time/alarmtimer.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 88c9c65..8cc43b8 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -261,15 +261,23 @@ static int alarmtimer_suspend(struct device *dev)

/* Setup an rtc timer to fire that far in the future */
rtc_timer_cancel(rtc, &rtctimer);
- rtc_read_time(rtc, &tm);
+ ret = rtc_read_time(rtc, &tm);
+ if (ret < 0)
+ goto rtc_err;
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);

/* Set alarm, if in the past reject suspend briefly to handle */
ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
- if (ret < 0)
+ if (ret == -ETIME)
__pm_wakeup_event(ws, MSEC_PER_SEC);
+ else if (ret < 0)
+ goto rtc_err;
return ret;
+ return 0;
static int alarmtimer_suspend(struct device *dev)

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