From: Riwen Lu <luriwen@kylinos.cn> stable inclusion from stable-v5.10.99 commit 460aa9d8734084628abae7b11b03d8daeff0955d bugzilla: https://gitee.com/openeuler/kernel/issues/I55O7H Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit ff164ae39b82ee483b24579c8e22a13a8ce5bd04 upstream. 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> Acked-by: Eric Wong <e@80x24.org> Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20220106084609.1223688-1-luriwen@kylinos.cn Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> # preparation for stable Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- 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 033dcc0645a5..9abb178adc10 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -99,7 +99,7 @@ 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; /* -- 2.20.1