[RFC PATCH v2 08/12] ARM: msm: use remapped PPI interrupts for local timer
From: Stephen Boyd <hidden>
Date: 2011-05-12 20:23:39
On 5/6/2011 3:33 AM, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c index 38b95e9..f063860 100644 --- a/arch/arm/mach-msm/timer.c +++ b/arch/arm/mach-msm/timer.c@@ -83,18 +85,7 @@ enum { static struct msm_clock msm_clocks[]; -static struct clock_event_device *local_clock_event; - -static irqreturn_t msm_timer_interrupt(int irq, void *dev_id) -{ - struct clock_event_device *evt = dev_id; - if (smp_processor_id() != 0) - evt = local_clock_event; - if (evt->event_handler == NULL) - return IRQ_HANDLED;
We just lost this important line. This prevents spurious interrupts from crashing the system.
- evt->event_handler(evt); - return IRQ_HANDLED; -}
I would prefer to keep the whole interrupt function because 1) MSM doesn't have a local_timer_ack() to implement and 2) I want to put code in here to stop the timer so that the timer doesn't wrap and cause another interrupt (yes the patches haven't been sent yet).
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+static int local_timer_inited; static cycle_t msm_read_timer_count(struct clocksource *cs) {@@ -140,6 +131,8 @@ static void msm_timer_set_mode(enum clock_event_mode mode, writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE); break; case CLOCK_EVT_MODE_UNUSED: + free_irq(evt->irq, evt);
This is crashing because evt->irq is never assigned in the case of CPU0's timer.
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@@ -253,10 +235,13 @@ static void __init msm_timer_init(void) printk(KERN_ERR "msm_timer_init: clocksource_register " "failed for %s\n", cs->name); - res = setup_irq(clock->irq.irq, &clock->irq); + irq = gic_ppi_to_vppi(clock->irq); + res = request_irq(irq, percpu_timer_handler, + IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING, + ce->name, ce);
How about assigning evt->irq to gic_ppi_to_vppi() and then use that instead of a local variable? That would fix the free_irq() bug up above. Also, percpu_timer_handler() is only defined in arm/kernel/smp.c which isn't going to be compiled in on non-SMP targets. This timer driver is common to all MSMs so it needs to work with SMP and non-SMP. -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.