3 files changed, 17 insertions, 9 deletions

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index fe6f7c2c9c6..bc3c745cb90 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -219,5 +219,7 @@ DECLARE_PER_CPU(struct cpu_usage, cpu_usage_array);
 extern void secondary_cpu_time_init(void);
 extern void iSeries_time_init_early(void);
 
+extern void decrementer_check_overflow(void);
+
 #endif /* __KERNEL__ */
 #endif /* __POWERPC_TIME_H */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 5c3c46948d9..745c1e7c10f 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -164,16 +164,13 @@ notrace void arch_local_irq_restore(unsigned long en)
          */
         local_paca->hard_enabled = en;
 
-#ifndef CONFIG_BOOKE
-        /* On server, re-trigger the decrementer if it went negative since
-         * some processors only trigger on edge transitions of the sign bit.
-         *
-         * BookE has a level sensitive decrementer (latches in TSR) so we
-         * don't need that
+        /*
+         * Trigger the decrementer if we have a pending event. Some processors
+         * only trigger on edge transitions of the sign bit. We might also
+         * have disabled interrupts long enough that the decrementer wrapped
+         * to positive.
          */
-        if ((int)mfspr(SPRN_DEC) < 0)
-                mtspr(SPRN_DEC, 1);
-#endif /* CONFIG_BOOKE */
+        decrementer_check_overflow();
 
         /*
          * Force the delivery of pending soft-disabled interrupts on PS3.
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 522bb1dfc35..5db163c9675 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -889,6 +889,15 @@ static void __init clocksource_init(void)
                clock->name, clock->mult, clock->shift);
 }
 
+void decrementer_check_overflow(void)
+{
+        u64 now = get_tb_or_rtc();
+        struct decrementer_clock *decrementer = &__get_cpu_var(decrementers);
+
+        if (now >= decrementer->next_tb)
+                set_dec(1);
+}
+
 static int decrementer_set_next_event(unsigned long evt,
                                       struct clock_event_device *dev)
 {