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-rw-r--r--arch/mips/kernel/cevt-r4k.c33
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 82bd2b2..d70c4d8 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -37,6 +37,24 @@ void mips_set_clock_mode(enum clock_event_mode mode,
DEFINE_PER_CPU(struct clock_event_device, mips_clockevent_device);
int cp0_timer_irq_installed;
+/*
+ * Possibly handle a performance counter interrupt.
+ * Return true if the timer interrupt should not be checked
+ */
+static inline int handle_perf_irq(int r2)
+{
+ /*
+ * The performance counter overflow interrupt may be shared with the
+ * timer interrupt (cp0_perfcount_irq < 0). If it is and a
+ * performance counter has overflowed (perf_irq() == IRQ_HANDLED)
+ * and we can't reliably determine if a counter interrupt has also
+ * happened (!r2) then don't check for a timer interrupt.
+ */
+ return (cp0_perfcount_irq < 0) &&
+ perf_irq() == IRQ_HANDLED &&
+ !r2;
+}
+
irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
{
const int r2 = cpu_has_mips_r2_r6;
@@ -50,27 +68,32 @@ irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
* the performance counter interrupt handler anyway.
*/
if (handle_perf_irq(r2))
- goto out;
+ return IRQ_HANDLED;
/*
* The same applies to performance counter interrupts. But with the
* above we now know that the reason we got here must be a timer
* interrupt. Being the paranoiacs we are we check anyway.
*/
- if (!r2 || (read_c0_cause() & (1 << 30))) {
+ if (!r2 || (read_c0_cause() & CAUSEF_TI)) {
/* Clear Count/Compare Interrupt */
write_c0_compare(read_c0_compare());
cd = &per_cpu(mips_clockevent_device, cpu);
cd->event_handler(cd);
+
+ return IRQ_HANDLED;
}
-out:
- return IRQ_HANDLED;
+ return IRQ_NONE;
}
struct irqaction c0_compare_irqaction = {
.handler = c0_compare_interrupt,
- .flags = IRQF_PERCPU | IRQF_TIMER,
+ /*
+ * IRQF_SHARED: The timer interrupt may be shared with other interrupts
+ * such as perf counter and FDC interrupts.
+ */
+ .flags = IRQF_PERCPU | IRQF_TIMER | IRQF_SHARED,
.name = "timer",
};
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