[patch 3/3] genirq: mark io_apic level interrupts to avoid resend

From: Thomas Gleixner
Date: Sun Aug 12 2007 - 11:45:56 EST


Level type interrupts do not need to be resent. It was also found that
some chipsets get confused in case of the resend.

Mark the ioapic level type interrupts as such to avoid the resend
functionality in the generic irq code.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
arch/i386/kernel/io_apic.c | 7 +++++--
arch/x86_64/kernel/io_apic.c | 7 +++++--
2 files changed, 10 insertions(+), 4 deletions(-)

Index: linux-2.6/arch/i386/kernel/io_apic.c
===================================================================
--- linux-2.6.orig/arch/i386/kernel/io_apic.c 2007-08-11 11:09:11.000000000 +0200
+++ linux-2.6/arch/i386/kernel/io_apic.c 2007-08-11 11:09:12.000000000 +0200
@@ -1256,12 +1256,15 @@ static struct irq_chip ioapic_chip;
static void ioapic_register_intr(int irq, int vector, unsigned long trigger)
{
if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
- trigger == IOAPIC_LEVEL)
+ trigger == IOAPIC_LEVEL) {
+ irq_desc[irq].status |= IRQ_LEVEL;
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_fasteoi_irq, "fasteoi");
- else
+ } else {
+ irq_desc[irq].status &= ~IRQ_LEVEL;
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_edge_irq, "edge");
+ }
set_intr_gate(vector, interrupt[irq]);
}

Index: linux-2.6/arch/x86_64/kernel/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86_64/kernel/io_apic.c 2007-08-11 11:09:11.000000000 +0200
+++ linux-2.6/arch/x86_64/kernel/io_apic.c 2007-08-11 11:09:12.000000000 +0200
@@ -800,12 +800,15 @@ static struct irq_chip ioapic_chip;

static void ioapic_register_intr(int irq, unsigned long trigger)
{
- if (trigger)
+ if (trigger) {
+ irq_desc[irq].status |= IRQ_LEVEL;
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_fasteoi_irq, "fasteoi");
- else
+ } else {
+ irq_desc[irq].status &= ~IRQ_LEVEL;
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_edge_irq, "edge");
+ }
}

static void setup_IO_APIC_irq(int apic, int pin, unsigned int irq,

--

-
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