From 210c1ca6f8d0c3e0f4b09a2113d9e00756c4066e Mon Sep 17 00:00:00 2001
From: Anton Blanchard <anton@samba.org>
Date: Sun, 10 May 2009 13:37:36 +0000
Subject: [PATCH] --- yaml --- r: 149653 b: refs/heads/master c:
 8d165db10772f238103c3e8f955c54145e5c07f3 h: refs/heads/master i:   149651:
 3db5c8d589b320807c5e1621b155ff17450739d6 v: v3

---
 [refs]                           |  2 +-
 trunk/arch/powerpc/kernel/time.c | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index aac94861b12e..f4cb6525ce2e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9aa4e7b1699d0fa197778da96de7e03fa2374f0a
+refs/heads/master: 8d165db10772f238103c3e8f955c54145e5c07f3
diff --git a/trunk/arch/powerpc/kernel/time.c b/trunk/arch/powerpc/kernel/time.c
index 48571ac56fb7..bee1443da763 100644
--- a/trunk/arch/powerpc/kernel/time.c
+++ b/trunk/arch/powerpc/kernel/time.c
@@ -109,7 +109,7 @@ static void decrementer_set_mode(enum clock_event_mode mode,
 static struct clock_event_device decrementer_clockevent = {
        .name           = "decrementer",
        .rating         = 200,
-       .shift          = 16,
+       .shift          = 0,	/* To be filled in */
        .mult           = 0,	/* To be filled in */
        .irq            = 0,
        .set_next_event = decrementer_set_next_event,
@@ -843,6 +843,22 @@ static void decrementer_set_mode(enum clock_event_mode mode,
 		decrementer_set_next_event(DECREMENTER_MAX, dev);
 }
 
+static void __init setup_clockevent_multiplier(unsigned long hz)
+{
+	u64 mult, shift = 32;
+
+	while (1) {
+		mult = div_sc(hz, NSEC_PER_SEC, shift);
+		if (mult && (mult >> 32UL) == 0UL)
+			break;
+
+		shift--;
+	}
+
+	decrementer_clockevent.shift = shift;
+	decrementer_clockevent.mult = mult;
+}
+
 static void register_decrementer_clockevent(int cpu)
 {
 	struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
@@ -860,8 +876,7 @@ static void __init init_decrementer_clockevent(void)
 {
 	int cpu = smp_processor_id();
 
-	decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC,
-					     decrementer_clockevent.shift);
+	setup_clockevent_multiplier(ppc_tb_freq);
 	decrementer_clockevent.max_delta_ns =
 		clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
 	decrementer_clockevent.min_delta_ns =