[PATCH v1] rtc: cmos: Evaluate century appropriate

From: Riwen Lu
Date: Thu Jan 06 2022 - 03:46:40 EST


There's limiting the year to 2069. When setting the rtc year to 2070,
reading it returns 1970. Evaluate century starting from 19 to count the
correct year.

$ sudo date -s 20700106
Mon 06 Jan 2070 12:00:00 AM CST
$ sudo hwclock -w
$ sudo hwclock -r
1970-01-06 12:00:49.604968+08:00

Fixes: 2a4daadd4d3e5071 ("rtc: cmos: ignore bogus century byte")

Signed-off-by: Riwen Lu <luriwen@xxxxxxxxxx>
---
drivers/rtc/rtc-mc146818-lib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c
index dcfaf09946ee..2065842f775d 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -104,7 +104,7 @@ unsigned int mc146818_get_time(struct rtc_time *time)
time->tm_year += real_year - 72;
#endif

- if (century > 20)
+ if (century > 19)
time->tm_year += (century - 19) * 100;

/*
--
2.25.1


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