Commit 2a4daadd authored Jan 06, 2019 by Eric Wong Committed by Alexandre Belloni Jan 22, 2019

rtc: cmos: ignore bogus century byte



Older versions of Libreboot and Coreboot had an invalid value
(`3' in my case) in the century byte affecting the GM45 in
the Thinkpad X200.  Not everybody's updated their firmwares,
and Linux <= 4.2 was able to read the RTC without problems,
so workaround this by ignoring invalid values.

Fixes: 3c217e51 ("rtc: cmos: century support")

Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Sylvain Chouleur <sylvain.chouleur@intel.com>
Cc: Patrick McDermott <patrick.mcdermott@libiquity.com>
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

parent 9a20b5e3

drivers/rtc/rtc-mc146818-lib.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -82,7 +82,7 @@ unsigned int mc146818_get_time(struct rtc_time *time)
		time->tm_year += real_year - 72;
		#endif

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

		/*