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Subject[PATCH 2/2] at91: use request_irq/free_irq instead of setup_irq/remove_irq
Date
This fixes a warning when using RT-Preempt.

WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1406 __free_irq+0xa4/0x210()
Trying to free already-free IRQ 0
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rt4+ #198
Hardware name: Atmel SAMA5
[<c0013008>] (unwind_backtrace) from [<c0010e90>] (show_stack+0x10/0x14)
[<c0010e90>] (show_stack) from [<c001a8c8>] (warn_slowpath_common+0x80/0xac)
[<c001a8c8>] (warn_slowpath_common) from [<c001a924>] (warn_slowpath_fmt+0x30/0x40)
[<c001a924>] (warn_slowpath_fmt) from [<c00473e8>] (__free_irq+0xa4/0x210)
[<c00473e8>] (__free_irq) from [<c0060820>] (clockevents_set_mode+0x28/0x5c)
[<c0060820>] (clockevents_set_mode) from [<c0060b40>] (clockevents_exchange_device+0x84/0x9c)
[<c0060b40>] (clockevents_exchange_device) from [<c006113c>] (tick_check_new_device+0x8c/0xac)
[<c006113c>] (tick_check_new_device) from [<c0060060>] (clockevents_register_device+0x5c/0x118)
[<c0060060>] (clockevents_register_device) from [<c067459c>] (clocksource_of_init+0x4c/0x8c)
[<c067459c>] (clocksource_of_init) from [<c065cb10>] (start_kernel+0x268/0x3c0)
[<c065cb10>] (start_kernel) from [<20008070>] (0x20008070)
---[ end trace 0000000000000001 ]---

Signed-off-by: David Dueck <davidcdueck@googlemail.com>
---
drivers/clocksource/timer-atmel-pit.c | 76 ++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 36 deletions(-)

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index d9c0b72..1de1ac8 100644
--- a/drivers/clocksource/timer-atmel-pit.c
+++ b/drivers/clocksource/timer-atmel-pit.c
@@ -90,7 +90,38 @@ static cycle_t read_pit_clk(struct clocksource *cs)
return elapsed;
}

-static struct irqaction at91sam926x_pit_irq;
+/*
+ * 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 ((data->clkevt.mode == CLOCK_EVT_MODE_PERIODIC) &&
+ (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)
*/
@@ -98,11 +129,16 @@ static void
pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
struct pit_data *data = clkevt_to_pit_data(dev);
+ int ret;

switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
- /* Set up irq handler */
- setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
+ ret = request_irq(data->irq, at91sam926x_pit_interrupt,
+ IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
+ "at91_tick", data);
+ if (ret)
+ pr_warn("Unable to request PIT irq!\n");
+
/* update clocksource counter */
data->cnt += data->cycle * PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
pit_write(data->base, AT91_PIT_MR,
@@ -116,7 +152,7 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
/* disable irq, leaving the clocksource active */
pit_write(data->base, AT91_PIT_MR,
(data->cycle - 1) | AT91_PIT_PITEN);
- remove_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
+ free_irq(data->irq, data);
break;
case CLOCK_EVT_MODE_RESUME:
break;
@@ -153,38 +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 ((data->clkevt.mode == CLOCK_EVT_MODE_PERIODIC) &&
- (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_common_init(struct pit_data *data)
--
2.4.4


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