From 231b0f80d19c96a2083fc735a116882e8db92df5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 3 Apr 2017 23:32:38 +0200 Subject: [PATCH] rtc: s35390a: make sure all members in the output are set MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit ac4d4f65bbcba478309de36929016d2618421ba1 upstream. The rtc core calls the .read_alarm with all fields initialized to 0. As the s35390a driver doesn't touch some fields the returned date is interpreted as a date in January 1900. So make sure all fields are set to -1; some of them are then overwritten with the right data depending on the hardware state. In mainline this is done by commit d68778b80dd7 ("rtc: initialize output parameter for read alarm to "uninitialized"") in the core. This is considered to dangerous for stable as it might have side effects for other rtc drivers that might for example rely on alarm->time.tm_sec being initialized to 0. Signed-off-by: Uwe Kleine-König Signed-off-by: Willy Tarreau --- drivers/rtc/rtc-s35390a.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c index f40afdd0e5f5..eae8bf25eeb3 100644 --- a/drivers/rtc/rtc-s35390a.c +++ b/drivers/rtc/rtc-s35390a.c @@ -265,6 +265,20 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) char buf[3], sts; int i, err; + /* + * initialize all members to -1 to signal the core that they are not + * defined by the hardware. + */ + alm->time.tm_sec = -1; + alm->time.tm_min = -1; + alm->time.tm_hour = -1; + alm->time.tm_mday = -1; + alm->time.tm_mon = -1; + alm->time.tm_year = -1; + alm->time.tm_wday = -1; + alm->time.tm_yday = -1; + alm->time.tm_isdst = -1; + err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); if (err < 0) return err; -- 2.20.1