--- /dev/null
+From 04005f6011e3b504cd4d791d9769f7cb9a3b2eae Mon Sep 17 00:00:00 2001
+From: John Stultz <john.stultz@linaro.org>
+Date: Tue, 10 Dec 2013 17:13:35 -0800
+Subject: timekeeping: Fix CLOCK_TAI timer/nanosleep delays
+
+From: John Stultz <john.stultz@linaro.org>
+
+commit 04005f6011e3b504cd4d791d9769f7cb9a3b2eae upstream.
+
+A think-o in the calculation of the monotonic -> tai time offset
+results in CLOCK_TAI timers and nanosleeps to expire late (the
+latency is ~2x the tai offset).
+
+Fix this by adding the tai offset from the realtime offset instead
+of subtracting.
+
+Cc: Sasha Levin <sasha.levin@oracle.com>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: Prarit Bhargava <prarit@redhat.com>
+Cc: Richard Cochran <richardcochran@gmail.com>
+Cc: Ingo Molnar <mingo@kernel.org>
+Signed-off-by: John Stultz <john.stultz@linaro.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ kernel/time/timekeeping.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/kernel/time/timekeeping.c
++++ b/kernel/time/timekeeping.c
+@@ -77,7 +77,7 @@ static void tk_set_wall_to_mono(struct t
+ tk->wall_to_monotonic = wtm;
+ set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+ tk->offs_real = timespec_to_ktime(tmp);
+- tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0));
++ tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
+ }
+
+ static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+@@ -595,7 +595,7 @@ s32 timekeeping_get_tai_offset(void)
+ static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
+ {
+ tk->tai_offset = tai_offset;
+- tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0));
++ tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
+ }
+
+ /**