Setup and remove the interrupt handler in clock event mode selection. This avoids calling the (shared) interrupt handler when the device is not used.
Signed-off-by: Alexandre Belloni <[email protected]> --- drivers/clocksource/timer-atmel-pit.c | 86 +++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 40 deletions(-) diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c index e64af62a186c..c77aafa7846e 100644 --- a/drivers/clocksource/timer-atmel-pit.c +++ b/drivers/clocksource/timer-atmel-pit.c @@ -96,15 +96,61 @@ static int pit_clkevt_shutdown(struct clock_event_device *dev) /* disable irq, leaving the clocksource active */ pit_write(data->base, AT91_PIT_MR, (data->cycle - 1) | AT91_PIT_PITEN); + + if (clockevent_state_periodic(dev)) + free_irq(data->irq, data); + return 0; } /* + * IRQ handler for the timer. + */ +static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id) +{ + struct pit_data *data = dev_id; + + /* + * irqs should be disabled here, but as the irq is shared they are only + * guaranteed to be off if the timer irq is registered first. + */ + WARN_ON_ONCE(!irqs_disabled()); + + /* 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); + + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +/* * Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16) */ static int pit_clkevt_set_periodic(struct clock_event_device *dev) { struct pit_data *data = clkevt_to_pit_data(dev); + int ret; + + /* Set up irq handler */ + ret = request_irq(data->irq, at91sam926x_pit_interrupt, + IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, + "at91_tick", data); + if (ret) { + pr_alert("Unable to setup IRQ\n"); + return ret; + } /* update clocksource counter */ data->cnt += data->cycle * PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR)); @@ -143,38 +189,6 @@ static void at91sam926x_pit_resume(struct clock_event_device *cedev) } /* - * IRQ handler for the timer. - */ -static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id) -{ - struct pit_data *data = dev_id; - - /* - * irqs should be disabled here, but as the irq is shared they are only - * guaranteed to be off if the timer irq is registered first. - */ - WARN_ON_ONCE(!irqs_disabled()); - - /* 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); - - return IRQ_HANDLED; - } - - return IRQ_NONE; -} - -/* * Set up both clocksource and clockevent support. */ static void __init at91sam926x_pit_dt_init(struct device_node *node) @@ -182,7 +196,6 @@ static void __init at91sam926x_pit_dt_init(struct device_node *node) struct pit_data *data; unsigned long pit_rate; unsigned bits; - int ret; data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) @@ -228,13 +241,6 @@ static void __init at91sam926x_pit_dt_init(struct device_node *node) data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS, clocksource_register_hz(&data->clksrc, pit_rate); - /* Set up irq handler */ - ret = request_irq(data->irq, at91sam926x_pit_interrupt, - IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, - "at91_tick", data); - if (ret) - panic(pr_fmt("Unable to setup IRQ\n")); - /* Set up and register clockevents */ data->clkevt.name = "pit"; data->clkevt.features = CLOCK_EVT_FEAT_PERIODIC; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
