When using RTC_ALM_SET or RTC_WKALM_SET with rtc_wkalrm.enabled not set, rtc_timer_enqueue() is not called and rtc_set_alarm() may succeed but the subsequent RTC_AIE_ON ioctl will fail. RTC_ALM_READ would also fail in that case.
Ensure rtc_set_alarm() fails when alarms are not supported to avoid letting programs think the alarms are working for a particular RTC when they are not. Signed-off-by: Alexandre Belloni <[email protected]> --- drivers/rtc/interface.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index ffcfe6319466..7cae46c6b9bf 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -442,6 +442,11 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; + if (!rtc->ops) + return -ENODEV; + else if (!rtc->ops->set_alarm) + return -EINVAL; + err = rtc_valid_tm(&alarm->time); if (err != 0) return err; -- 2.17.1
