2 files changed, 14 insertions, 11 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index d4646b48dc4a..18a1baf31f2d 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -188,6 +188,7 @@ struct clocksource {
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
         /* Watchdog related data, used by the framework */
         struct list_head wd_list;
+        cycle_t cs_last;
         cycle_t wd_last;
 #endif
 } ____cacheline_aligned;
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 1c95fd677328..e0980f0d9a0a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -185,7 +185,6 @@ static struct clocksource *watchdog;
 static struct timer_list watchdog_timer;
 static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
 static DEFINE_SPINLOCK(watchdog_lock);
-static cycle_t watchdog_last;
 static int watchdog_running;
 
 static int clocksource_watchdog_kthread(void *data);
@@ -254,11 +253,6 @@ static void clocksource_watchdog(unsigned long data)
         if (!watchdog_running)
                 goto out;
 
-        wdnow = watchdog->read(watchdog);
-        wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask,
-                                     watchdog->mult, watchdog->shift);
-        watchdog_last = wdnow;
-
         list_for_each_entry(cs, &watchdog_list, wd_list) {
 
                 /* Clocksource already marked unstable? */
@@ -268,19 +262,28 @@ static void clocksource_watchdog(unsigned long data)
                         continue;
                 }
 
+                local_irq_disable();
                 csnow = cs->read(cs);
+                wdnow = watchdog->read(watchdog);
+                local_irq_enable();
 
                 /* Clocksource initialized ? */
                 if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
                         cs->flags |= CLOCK_SOURCE_WATCHDOG;
-                        cs->wd_last = csnow;
+                        cs->wd_last = wdnow;
+                        cs->cs_last = csnow;
                         continue;
                 }
 
-                /* Check the deviation from the watchdog clocksource. */
-                cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
+                wd_nsec = clocksource_cyc2ns((wdnow - cs->wd_last) & watchdog->mask,
+                                             watchdog->mult, watchdog->shift);
+
+                cs_nsec = clocksource_cyc2ns((csnow - cs->cs_last) &
                                              cs->mask, cs->mult, cs->shift);
-                cs->wd_last = csnow;
+                cs->cs_last = csnow;
+                cs->wd_last = wdnow;
+
+                /* Check the deviation from the watchdog clocksource. */
                 if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
                         clocksource_unstable(cs, cs_nsec - wd_nsec);
                         continue;
@@ -318,7 +321,6 @@ static inline void clocksource_start_watchdog(void)
                 return;
         init_timer(&watchdog_timer);
         watchdog_timer.function = clocksource_watchdog;
-        watchdog_last = watchdog->read(watchdog);
         watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
         add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
         watchdog_running = 1;