From 76d2160147f43f982dfe881404cfde9fd0a9da21 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 16 Feb 2007 01:28:24 -0800 Subject: [PATCH] [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 Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/i8259.c | 1 + arch/x86_64/kernel/i8259.c | 1 + kernel/irq/chip.c | 17 ++++++++++------- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/arch/i386/kernel/i8259.c b/arch/i386/kernel/i8259.c index 255b1af9a054..03abfdb1a6e4 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 d73c79e821f1..01e2cf0bdeb1 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 475e8a71bcdc..76a9106a0bf4 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; }