If an alarm interrupt raises just after the CR register is written and before the ACKUPD is unmasked the ACKUPD bit might be cleaned up without waking up the waiting thread.
Unmask the ACKUPD interrupt before writing the CR register so that the ACKUPD cannot be lost. Signed-off-by: Boris BREZILLON <boris.brezil...@free-electrons.com> Reported-by: Bryan Evenson <beven...@melinkcorp.com> --- Hello Bryan, Could you try to apply this patch and tell me if it fixes your bug ? Best Regards, Boris drivers/rtc/rtc-at91rm9200.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 3281c90..c16c423 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -163,9 +163,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) /* Stop Time/Calendar from counting */ cr = at91_rtc_read(AT91_RTC_CR); + at91_rtc_write_ier(AT91_RTC_ACKUPD); at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); - at91_rtc_write_ier(AT91_RTC_ACKUPD); wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ at91_rtc_write_idr(AT91_RTC_ACKUPD); -- 1.8.3.2 -- 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/