clocksource/drivers/timer-atmel-pit: Simplify IRQ handler

Because the PIT is also a proper clocksource, the timekeeping code  is
already able to handle lost ticks.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index 91cf04704ed1..6555821bbdae 100644
--- a/drivers/clocksource/timer-atmel-pit.c
+++ b/drivers/clocksource/timer-atmel-pit.c
@@ -152,15 +152,10 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
         /* The PIT interrupt may be disabled, and is shared */
         if (clockevent_state_periodic(&data->clkevt) &&
             (pit_read(data->base, AT91_PIT_SR) & AT91_PIT_PITS)) {
-                unsigned nr_ticks;
-
                 /* Get number of ticks performed before irq, and ack it */
-                nr_ticks = PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
-                do {
-                        data->cnt += data->cycle;
-                        data->clkevt.event_handler(&data->clkevt);
-                        nr_ticks--;
-                } while (nr_ticks);
+                data->cnt += data->cycle * PIT_PICNT(pit_read(data->base,
+                                                              AT91_PIT_PIVR));
+                data->clkevt.event_handler(&data->clkevt);
 
                 return IRQ_HANDLED;
         }