driver/rtc/class.c: check the error after rtc_read_time()

In rtc_suspend() and rtc_resume(), the error after rtc_read_time() is not
checked.  If rtc device fail to read time, we cannot guarantee the
following process.

Add the verification code for returned rtc_read_time() error.

Signed-off-by: Hyogi Gim <hyogi.gim@lge.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 589351e..38e26be 100644 (file)
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -53,6 +53,7 @@ static int rtc_suspend(struct device *dev)
        struct rtc_device       *rtc = to_rtc_device(dev);
        struct rtc_time         tm;
        struct timespec         delta, delta_delta;
+       int err;
 
        if (has_persistent_clock())
                return 0;
@@ -61,7 +62,12 @@ static int rtc_suspend(struct device *dev)
                return 0;
 
        /* snapshot the current RTC and system time at suspend*/
-       rtc_read_time(rtc, &tm);
+       err = rtc_read_time(rtc, &tm);
+       if (err < 0) {
+               pr_debug("%s:  fail to read rtc time\n", dev_name(&rtc->dev));
+               return 0;
+       }
+
        getnstimeofday(&old_system);
        rtc_tm_to_time(&tm, &old_rtc.tv_sec);
 
@@ -94,6 +100,7 @@ static int rtc_resume(struct device *dev)
        struct rtc_time         tm;
        struct timespec         new_system, new_rtc;
        struct timespec         sleep_time;
+       int err;
 
        if (has_persistent_clock())
                return 0;
@@ -104,7 +111,12 @@ static int rtc_resume(struct device *dev)
 
        /* snapshot the current rtc and system time at resume */
        getnstimeofday(&new_system);
-       rtc_read_time(rtc, &tm);
+       err = rtc_read_time(rtc, &tm);
+       if (err < 0) {
+               pr_debug("%s:  fail to read rtc time\n", dev_name(&rtc->dev));
+               return 0;
+       }
+
        if (rtc_valid_tm(&tm) != 0) {
                pr_debug("%s:  bogus resume time\n", dev_name(&rtc->dev));
                return 0;