rtc: ds1307: prevent to set the specific time value

When using the time over "date 2038-01-19 03:14", Systemd is displaying
the below log as spamming.

"systemd[1]: Time has been changed"

This patch is workaround for preventing to set the value over
"2038-01-19".

Refer to https://patchwork.kernel.org/patch/7133531/

Change-Id: Iab3823b63d738c0c63d4cee439ab53da335f4ef0
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 1f0ee02..eaf2c85 100644 (file)
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -392,6 +392,16 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
        int             tmp;
        u8              *buf = ds1307->regs;
 
+       /*
+        * WORKAROUND:
+        * If try to set 2038/01/19, prevent to set the value.
+        */
+       if (t->tm_year >= 138 && t->tm_mon > 0 && t->tm_mday > 18) {
+               dev_err(dev, "Can't set year = %d, mon = %d, mday = %d\n",
+                       t->tm_year + 1900, t->tm_mon, t->tm_mday);
+               return -EINVAL;
+       }
+
        dev_dbg(dev, "%s secs=%d, mins=%d, "
                "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
                "write", t->tm_sec, t->tm_min,