diff options
Diffstat (limited to 'drivers/rtc/rtc-mrst.c')
| -rw-r--r-- | drivers/rtc/rtc-mrst.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c index d33544802a2e..bb21f443fb70 100644 --- a/drivers/rtc/rtc-mrst.c +++ b/drivers/rtc/rtc-mrst.c @@ -76,12 +76,15 @@ static inline unsigned char vrtc_is_updating(void) /* * rtc_time's year contains the increment over 1900, but vRTC's YEAR * register can't be programmed to value larger than 0x64, so vRTC - * driver chose to use 1960 (1970 is UNIX time start point) as the base, + * driver chose to use 1972 (1970 is UNIX time start point) as the base, * and does the translation at read/write time. * - * Why not just use 1970 as the offset? it's because using 1960 will + * Why not just use 1970 as the offset? it's because using 1972 will * make it consistent in leap year setting for both vrtc and low-level - * physical rtc devices. + * physical rtc devices. Then why not use 1960 as the offset? If we use + * 1960, for a device's first use, its YEAR register is 0 and the system + * year will be parsed as 1960 which is not a valid UNIX time and will + * cause many applications to fail mysteriously. */ static int mrst_read_time(struct device *dev, struct rtc_time *time) { @@ -99,10 +102,10 @@ static int mrst_read_time(struct device *dev, struct rtc_time *time) time->tm_year = vrtc_cmos_read(RTC_YEAR); spin_unlock_irqrestore(&rtc_lock, flags); - /* Adjust for the 1960/1900 */ - time->tm_year += 60; + /* Adjust for the 1972/1900 */ + time->tm_year += 72; time->tm_mon--; - return RTC_24H; + return rtc_valid_tm(time); } static int mrst_set_time(struct device *dev, struct rtc_time *time) @@ -119,9 +122,9 @@ static int mrst_set_time(struct device *dev, struct rtc_time *time) min = time->tm_min; sec = time->tm_sec; - if (yrs < 70 || yrs > 138) + if (yrs < 72 || yrs > 138) return -EINVAL; - yrs -= 60; + yrs -= 72; spin_lock_irqsave(&rtc_lock, flags); |