diff options
Diffstat (limited to 'drivers/rtc/rtc-dev.c')
| -rw-r--r-- | drivers/rtc/rtc-dev.c | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 671b14ec28bb..f4e5f0040ff7 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -277,12 +277,48 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, alarm.enabled = 0; alarm.pending = 0; - alarm.time.tm_mday = -1; - alarm.time.tm_mon = -1; - alarm.time.tm_year = -1; alarm.time.tm_wday = -1; alarm.time.tm_yday = -1; alarm.time.tm_isdst = -1; + + /* RTC_ALM_SET alarms may be up to 24 hours in the future. + * Rather than expecting every RTC to implement "don't care" + * for day/month/year fields, just force the alarm to have + * the right values for those fields. + * + * RTC_WKALM_SET should be used instead. Not only does it + * eliminate the need for a separate RTC_AIE_ON call, it + * doesn't have the "alarm 23:59:59 in the future" race. + * + * NOTE: some legacy code may have used invalid fields as + * wildcards, exposing hardware "periodic alarm" capabilities. + * Not supported here. + */ + { + unsigned long now, then; + + err = rtc_read_time(rtc, &tm); + if (err < 0) + return err; + rtc_tm_to_time(&tm, &now); + + alarm.time.tm_mday = tm.tm_mday; + alarm.time.tm_mon = tm.tm_mon; + alarm.time.tm_year = tm.tm_year; + err = rtc_valid_tm(&alarm.time); + if (err < 0) + return err; + rtc_tm_to_time(&alarm.time, &then); + + /* alarm may need to wrap into tomorrow */ + if (then < now) { + rtc_time_to_tm(now + 24 * 60 * 60, &tm); + alarm.time.tm_mday = tm.tm_mday; + alarm.time.tm_mon = tm.tm_mon; + alarm.time.tm_year = tm.tm_year; + } + } + err = rtc_set_alarm(rtc, &alarm); break; |