1 files changed, 9 insertions, 14 deletions

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 39013867cbd6..4194e59e14cd 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -41,26 +41,21 @@ static void rtc_device_release(struct device *dev)
  * system's wall clock; restore it on resume().
  */
 
-static struct timespec  delta;
 static time_t           oldtime;
+static struct timespec  oldts;
 
 static int rtc_suspend(struct device *dev, pm_message_t mesg)
 {
         struct rtc_device       *rtc = to_rtc_device(dev);
         struct rtc_time         tm;
-        struct timespec         ts = current_kernel_time();
 
         if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
                 return 0;
 
         rtc_read_time(rtc, &tm);
+        ktime_get_ts(&oldts);
         rtc_tm_to_time(&tm, &oldtime);
 
-        /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */
-        set_normalized_timespec(&delta,
-                                ts.tv_sec - oldtime,
-                                ts.tv_nsec - (NSEC_PER_SEC >> 1));
-
         return 0;
 }
 
@@ -70,10 +65,12 @@ static int rtc_resume(struct device *dev)
         struct rtc_time         tm;
         time_t                  newtime;
         struct timespec         time;
+        struct timespec         newts;
 
         if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
                 return 0;
 
+        ktime_get_ts(&newts);
         rtc_read_time(rtc, &tm);
         if (rtc_valid_tm(&tm) != 0) {
                 pr_debug("%s:  bogus resume time\n", dev_name(&rtc->dev));
@@ -85,15 +82,13 @@ static int rtc_resume(struct device *dev)
                         pr_debug("%s:  time travel!\n", dev_name(&rtc->dev));
                 return 0;
         }
+        /* calculate the RTC time delta */
+        set_normalized_timespec(&time, newtime - oldtime, 0);
 
-        /* restore wall clock using delta against this RTC;
-         * adjust again for avg 1/2 second RTC sampling error
-         */
-        set_normalized_timespec(&time,
-                                newtime + delta.tv_sec,
-                                (NSEC_PER_SEC >> 1) + delta.tv_nsec);
-        do_settimeofday(&time);
+        /* subtract kernel time between rtc_suspend to rtc_resume */
+        time = timespec_sub(time, timespec_sub(newts, oldts));
 
+        timekeeping_inject_sleeptime(&time);
         return 0;
 }