[PATCH 3.11 092/208] ARM: fix footbridge clockevent device

[Luis Henriques]

3.11.10.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Russell King <rmk+kernel at arm.linux.org.uk>

commit 4ff859fe1dc0da0f87bbdfff78f527898878fa4a upstream.

The clockevents code was being told that the footbridge clock event
device ticks at 16x the rate which it actually does.  This leads to
timekeeping problems since it allows the clocksource to wrap before
the kernel notices.  Fix this by using the correct clock.

Fixes: 4e8d76373c9fd ("ARM: footbridge: convert to clockevents/clocksource")
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/arm/mach-footbridge/dc21285-timer.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c
index 9ee78f7..782f6c7 100644
--- a/arch/arm/mach-footbridge/dc21285-timer.c
+++ b/arch/arm/mach-footbridge/dc21285-timer.c
@@ -96,11 +96,12 @@ static struct irqaction footbridge_timer_irq = {
 void __init footbridge_timer_init(void)
 {
 	struct clock_event_device *ce = &ckevt_dc21285;
+	unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);
 
-	clocksource_register_hz(&cksrc_dc21285, (mem_fclk_21285 + 8) / 16);
+	clocksource_register_hz(&cksrc_dc21285, rate);
 
 	setup_irq(ce->irq, &footbridge_timer_irq);
 
 	ce->cpumask = cpumask_of(smp_processor_id());
-	clockevents_config_and_register(ce, mem_fclk_21285, 0x4, 0xffffff);
+	clockevents_config_and_register(ce, rate, 0x4, 0xffffff);
 }
-- 
1.8.3.2