If we settime between 1970 and 2000. for example: $ date 052915571978 $ hwclock -w it will be wrong, this patch fix it. Signed-off-by: Linkui <xiaolinkui@xxxxxxxxxx> --- drivers/rtc/rtc-ds1307.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index a13e59edff53..8c218a16569d 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -425,7 +425,9 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t) t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f); tmp = regs[DS1307_REG_MONTH] & 0x1f; t->tm_mon = bcd2bin(tmp) - 1; - t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100; + t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]); + if (t->tm_year >= 0 && t->tm_year <= 69) + t->tm_year += 100; if (regs[chip->century_reg] & chip->century_bit && IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY)) @@ -454,7 +456,7 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t) t->tm_hour, t->tm_mday, t->tm_mon, t->tm_year, t->tm_wday); - if (t->tm_year < 100) + if (t->tm_year < 0) return -EINVAL; #ifdef CONFIG_RTC_DRV_DS1307_CENTURY @@ -472,8 +474,9 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t) regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday); regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1); - /* assume 20YY not 19YY */ - tmp = t->tm_year - 100; + tmp = t->tm_year; + if (tmp >= 100 && tmp <= 169) + tmp -= 100; regs[DS1307_REG_YEAR] = bin2bcd(tmp); if (chip->century_enable_bit) -- 2.17.0