From: Colin Ian King <colin.k...@canonical.com> The current enqueuing does not trigger an alarm if there are any expired timers on the timerqueue. This can occur when a RTC wake alarm is used to wake a machine out of hibernate and the resumed state has old expired timers that have not been removed from the timer queue.
This fix skips over any expired timers and will trigger an alarm if there are no other pending timers on the timerqueue. The bug was found running the example RTC timer program from Documentation/rtc.txt; it runs fine before a hibernate but will block forever on RTC reads after a resume from a hibernate that is woken up using a RTC wakealarm. Signed-off-by: Colin Ian King <colin.k...@canonical.com> --- drivers/rtc/interface.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 5b2717f..ca9d9fc 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -780,9 +780,23 @@ EXPORT_SYMBOL_GPL(rtc_irq_set_freq); */ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) { + struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); + struct rtc_time tm; + ktime_t now; + timer->enabled = 1; + __rtc_read_time(rtc, &tm); + now = rtc_tm_to_ktime(tm); + + /* Skip over expired timers */ + while (next) { + if (next->expires.tv64 >= now.tv64) + break; + next = timerqueue_iterate_next(next); + } + timerqueue_add(&rtc->timerqueue, &timer->node); - if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { + if (!next) { struct rtc_wkalrm alarm; int err; alarm.time = rtc_ktime_to_tm(timer->node.expires); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/