struct k_clock process = {
                .clock_getres   = process_cpu_clock_getres,
                .clock_get      = process_cpu_clock_get,
-               .clock_set      = do_posix_clock_nosettime,
                .timer_create   = process_cpu_timer_create,
                .nsleep         = process_cpu_nsleep,
                .nsleep_restart = process_cpu_nsleep_restart,
        struct k_clock thread = {
                .clock_getres   = thread_cpu_clock_getres,
                .clock_get      = thread_cpu_clock_get,
-               .clock_set      = do_posix_clock_nosettime,
                .timer_create   = thread_cpu_timer_create,
        };
        struct timespec ts;
 
        return 0;
 }
 
-static inline int common_clock_set(const clockid_t which_clock,
-                                  const struct timespec *tp)
-{
-       return do_sys_settimeofday(tp, NULL);
-}
-
 static int common_timer_create(struct k_itimer *new_timer)
 {
        hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
        return 1;
 }
 
+/* Set clock_realtime */
+static int posix_clock_realtime_set(const clockid_t which_clock,
+                                   const struct timespec *tp)
+{
+       return do_sys_settimeofday(tp, NULL);
+}
+
 /*
  * Get monotonic time for posix timers
  */
 {
        struct k_clock clock_realtime = {
                .clock_getres   = hrtimer_get_res,
+               .clock_set      = posix_clock_realtime_set,
                .nsleep         = common_nsleep,
                .nsleep_restart = hrtimer_nanosleep_restart,
        };
        struct k_clock clock_monotonic = {
                .clock_getres   = hrtimer_get_res,
                .clock_get      = posix_ktime_get_ts,
-               .clock_set      = do_posix_clock_nosettime,
                .nsleep         = common_nsleep,
                .nsleep_restart = hrtimer_nanosleep_restart,
        };
        struct k_clock clock_monotonic_raw = {
                .clock_getres   = hrtimer_get_res,
                .clock_get      = posix_get_monotonic_raw,
-               .clock_set      = do_posix_clock_nosettime,
                .timer_create   = no_timer_create,
        };
        struct k_clock clock_realtime_coarse = {
                .clock_getres   = posix_get_coarse_res,
                .clock_get      = posix_get_realtime_coarse,
-               .clock_set      = do_posix_clock_nosettime,
                .timer_create   = no_timer_create,
        };
        struct k_clock clock_monotonic_coarse = {
                .clock_getres   = posix_get_coarse_res,
                .clock_get      = posix_get_monotonic_coarse,
-               .clock_set      = do_posix_clock_nosettime,
                .timer_create   = no_timer_create,
        };
 
        }
 }
 
-/* Not available / possible... functions */
-int do_posix_clock_nosettime(const clockid_t clockid, const struct timespec *tp)
-{
-       return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(do_posix_clock_nosettime);
-
 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
                const struct timespec __user *, tp)
 {
+       struct k_clock *kc = clockid_to_kclock(which_clock);
        struct timespec new_tp;
 
-       if (invalid_clockid(which_clock))
+       if (!kc || !kc->clock_set)
                return -EINVAL;
+
        if (copy_from_user(&new_tp, tp, sizeof (*tp)))
                return -EFAULT;
 
-       return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp));
+       return kc->clock_set(which_clock, &new_tp);
 }
 
 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,