rtc: ds1307: Clamp year to valid BCD (0-99) in set_time()

`tm_year` may go up to 299 if the device supports the
century bit. Therefore, subtracting may not give us
a valid 2-digit number, but modulo does.

Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20240611072411.671600-2-csokas.bence@prolan.hu
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Csókás, Bence 2024-06-11 09:24:09 +02:00 committed by Alexandre Belloni
parent 35a34f09ba
commit 68f78c720d

View File

@ -359,7 +359,7 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
/* assume 20YY not 19YY */
tmp = t->tm_year - 100;
tmp = t->tm_year % 100;
regs[DS1307_REG_YEAR] = bin2bcd(tmp);
if (chip->century_enable_bit)