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* [PATCH v1] rtc: cmos: Evaluate century appropriate
@ 2022-01-06  8:46 Riwen Lu
  2022-01-11 18:07 ` Eric Wong
  2022-01-16 22:58 ` Alexandre Belloni
  0 siblings, 2 replies; 4+ messages in thread
From: Riwen Lu @ 2022-01-06  8:46 UTC (permalink / raw)
  To: a.zummo, alexandre.belloni, e; +Cc: linux-rtc, linux-kernel, Riwen Lu

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@kylinos.cn>
---
 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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^ permalink raw reply related	[flat|nested] 4+ messages in thread
[parent not found: <20220106084609.1223688-1-luriwen () kylinos ! cn>]

end of thread, other threads:[~2022-01-16 22:58 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-01-06  8:46 [PATCH v1] rtc: cmos: Evaluate century appropriate Riwen Lu
2022-01-11 18:07 ` Eric Wong
2022-01-16 22:58 ` Alexandre Belloni
     [not found] <20220106084609.1223688-1-luriwen () kylinos ! cn>
2022-01-07 12:43 ` Mateusz Jończyk

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