rtc: ensure rtc_set_alarm fails when alarms are not supported

[ Upstream commit abfdff44bc38e9e2ef7929f633fb8462632299d4 ]

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 <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexandre Belloni 2018-06-05 23:09:14 +02:00 committed by syphyr
parent 3068d94fba
commit e411eea119
1 changed files with 5 additions and 0 deletions

View File

@ -381,6 +381,11 @@ 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;