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>

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index 91cf047..6555821 100644 (file)
--- 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;
        }