3 files changed, 15 insertions, 2 deletions

diff --git a/include/linux/time.h b/include/linux/time.h
index 476e1d7b2c37..a3ab6a814a9c 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -128,6 +128,7 @@ static inline bool has_persistent_clock(void)
 
 extern void read_persistent_clock(struct timespec *ts);
 extern void read_boot_clock(struct timespec *ts);
+extern int persistent_clock_is_local;
 extern int update_persistent_clock(struct timespec now);
 void timekeeping_init(void);
 extern int timekeeping_suspended;
diff --git a/kernel/time.c b/kernel/time.c
index d226c6a3fd28..c2a27dd93142 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -115,6 +115,12 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
 }
 
 /*
+ * Indicates if there is an offset between the system clock and the hardware
+ * clock/persistent clock/rtc.
+ */
+int persistent_clock_is_local;
+
+/*
  * Adjust the time obtained from the CMOS to be UTC time instead of
  * local time.
  *
@@ -135,6 +141,8 @@ static inline void warp_clock(void)
         struct timespec adjust;
 
         adjust = current_kernel_time();
+        if (sys_tz.tz_minuteswest != 0)
+                persistent_clock_is_local = 1;
         adjust.tv_sec += sys_tz.tz_minuteswest * 60;
         do_settimeofday(&adjust);
 }
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 313b161504b7..b10a42bb0165 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -511,13 +511,17 @@ static void sync_cmos_clock(struct work_struct *work)
 
         getnstimeofday(&now);
         if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) {
+                struct timespec adjust = now;
+
                 fail = -ENODEV;
+                if (persistent_clock_is_local)
+                        adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
-                fail = update_persistent_clock(now);
+                fail = update_persistent_clock(adjust);
 #endif
 #ifdef CONFIG_RTC_SYSTOHC
                 if (fail == -ENODEV)
-                        fail = rtc_set_ntp_time(now);
+                        fail = rtc_set_ntp_time(adjust);
 #endif
         }