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authorIngo Molnar <mingo@elte.hu>2007-02-16 09:28:24 (GMT)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-16 16:14:00 (GMT)
commit76d2160147f43f982dfe881404cfde9fd0a9da21 (patch)
tree5140d838f64e8494abd4942b4e2ddf2ddee69046
parent1f2ea0837dbc263ce2a2512c4e73c83df68a6a55 (diff)
downloadlinux-76d2160147f43f982dfe881404cfde9fd0a9da21.tar.xz
[PATCH] genirq: do not mask interrupts by default
Never mask interrupts immediately upon request. Disabling interrupts in high-performance codepaths is rare, and on the other hand this change could recover lost edges (or even other types of lost interrupts) by conservatively only masking interrupts after they happen. (NOTE: with this change the highlevel irq-disable code still soft-disables this IRQ line - and if such an interrupt happens then the IRQ flow handler keeps the IRQ masked.) Mark i8529A controllers as 'never loses an edge'. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/i386/kernel/i8259.c1
-rw-r--r--arch/x86_64/kernel/i8259.c1
-rw-r--r--kernel/irq/chip.c17
3 files changed, 12 insertions, 7 deletions
diff --git a/arch/i386/kernel/i8259.c b/arch/i386/kernel/i8259.c
index 255b1af..03abfdb 100644
--- a/arch/i386/kernel/i8259.c
+++ b/arch/i386/kernel/i8259.c
@@ -41,6 +41,7 @@ static void mask_and_ack_8259A(unsigned int);
static struct irq_chip i8259A_chip = {
.name = "XT-PIC",
.mask = disable_8259A_irq,
+ .disable = disable_8259A_irq,
.unmask = enable_8259A_irq,
.mask_ack = mask_and_ack_8259A,
};
diff --git a/arch/x86_64/kernel/i8259.c b/arch/x86_64/kernel/i8259.c
index d73c79e..01e2cf0 100644
--- a/arch/x86_64/kernel/i8259.c
+++ b/arch/x86_64/kernel/i8259.c
@@ -103,6 +103,7 @@ static void mask_and_ack_8259A(unsigned int);
static struct irq_chip i8259A_chip = {
.name = "XT-PIC",
.mask = disable_8259A_irq,
+ .disable = disable_8259A_irq,
.unmask = enable_8259A_irq,
.mask_ack = mask_and_ack_8259A,
};
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 475e8a7..76a9106 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -230,10 +230,6 @@ static void default_enable(unsigned int irq)
*/
static void default_disable(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
-
- if (!(desc->status & IRQ_DELAYED_DISABLE))
- desc->chip->mask(irq);
}
/*
@@ -298,13 +294,18 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
- desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
action = desc->action;
- if (unlikely(!action || (desc->status & IRQ_DISABLED)))
+ if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+ if (desc->chip->mask)
+ desc->chip->mask(irq);
+ desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+ desc->status |= IRQ_PENDING;
goto out_unlock;
+ }
+ desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING);
desc->status |= IRQ_INPROGRESS;
spin_unlock(&desc->lock);
@@ -396,11 +397,13 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
/*
* If its disabled or no action available
- * keep it masked and get out of here
+ * then mask it and get out of here:
*/
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
desc->status |= IRQ_PENDING;
+ if (desc->chip->mask)
+ desc->chip->mask(irq);
goto out;
}