From f8b34c3fd5a3fe7820952400ebbbc0528ec80686 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Sat, 25 Jan 2014 00:42:37 +0530 Subject: [PATCH] ARC: [clockevent] simplify timer ISR * Remove one liner IRQ ACK accessor, it was coming in the way of readability. Signed-off-by: Vineet Gupta --- arch/arc/kernel/time.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c index a8787bcb..71c4252 100644 --- a/arch/arc/kernel/time.c +++ b/arch/arc/kernel/time.c @@ -155,22 +155,6 @@ static void arc_timer_event_setup(unsigned int limit) write_aux_reg(ARC_REG_TIMER0_CTRL, TIMER_CTRL_IE | TIMER_CTRL_NH); } -/* - * Acknowledge the interrupt (oneshot) and optionally re-arm it (periodic) - * -Any write to CTRL Reg will ack the intr (NH bit: Count when not halted) - * -Rearming is done by setting the IE bit - * - * Small optimisation: Normal code would have been - * if (irq_reenable) - * CTRL_REG = (IE | NH); - * else - * CTRL_REG = NH; - * However since IE is BIT0 we can fold the branch - */ -static void arc_timer_event_ack(unsigned int irq_reenable) -{ - write_aux_reg(ARC_REG_TIMER0_CTRL, irq_reenable | TIMER_CTRL_NH); -} static int arc_clkevent_set_next_event(unsigned long delta, struct clock_event_device *dev) @@ -207,10 +191,22 @@ static DEFINE_PER_CPU(struct clock_event_device, arc_clockevent_device) = { static irqreturn_t timer_irq_handler(int irq, void *dev_id) { - struct clock_event_device *clk = this_cpu_ptr(&arc_clockevent_device); + /* + * Note that generic IRQ core could have passed @evt for @dev_id if + * irq_set_chip_and_handler() asked for handle_percpu_devid_irq() + */ + struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device); + int irq_reenable = evt->mode == CLOCK_EVT_MODE_PERIODIC; + + /* + * Any write to CTRL reg ACks the interrupt, we rewrite the + * Count when [N]ot [H]alted bit. + * And re-arm it if perioid by [I]nterrupt [E]nable bit + */ + write_aux_reg(ARC_REG_TIMER0_CTRL, irq_reenable | TIMER_CTRL_NH); + + evt->event_handler(evt); - arc_timer_event_ack(clk->mode == CLOCK_EVT_MODE_PERIODIC); - clk->event_handler(clk); return IRQ_HANDLED; } -- 2.7.4