timekeeping: Simplify tai updating from do_adjtimex

Since we are taking the timekeeping locks, just go ahead
and update any tai change directly, rather then dropping
the lock and calling a function that will just take it again.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index d10bd734b151..f93f60cd97ad 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1618,9 +1618,10 @@ EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
  */
 int do_adjtimex(struct timex *txc)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long flags;
         struct timespec ts;
-        s32 tai, orig_tai;
+        s32 tai;
         int ret;
 
         /* Validate the data before disabling interrupts */
@@ -1640,19 +1641,17 @@ int do_adjtimex(struct timex *txc)
         }
 
         getnstimeofday(&ts);
-        orig_tai = tai = timekeeping_get_tai_offset();
 
         raw_spin_lock_irqsave(&timekeeper_lock, flags);
         write_seqcount_begin(&timekeeper_seq);
 
+        tai = tk->tai_offset;
         ret = __do_adjtimex(txc, &ts, &tai);
 
+        __timekeeping_set_tai_offset(tk, tai);
         write_seqcount_end(&timekeeper_seq);
         raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
-        if (tai != orig_tai)
-                timekeeping_set_tai_offset(tai);
-
         return ret;
 }