aboutsummaryrefslogtreecommitdiff
path: root/kernel/irq/spurious.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/irq/spurious.c')
-rw-r--r--kernel/irq/spurious.c115
1 files changed, 112 insertions, 3 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index f6297c30690..7df9abd5ec8 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -11,6 +11,83 @@
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
+static int irqfixup;
+
+/*
+ * Recovery handler for misrouted interrupts.
+ */
+
+static int misrouted_irq(int irq, struct pt_regs *regs)
+{
+ int i;
+ irq_desc_t *desc;
+ int ok = 0;
+ int work = 0; /* Did we do work for a real IRQ */
+
+ for(i = 1; i < NR_IRQS; i++) {
+ struct irqaction *action;
+
+ if (i == irq) /* Already tried */
+ continue;
+ desc = &irq_desc[i];
+ spin_lock(&desc->lock);
+ action = desc->action;
+ /* Already running on another processor */
+ if (desc->status & IRQ_INPROGRESS) {
+ /*
+ * Already running: If it is shared get the other
+ * CPU to go looking for our mystery interrupt too
+ */
+ if (desc->action && (desc->action->flags & SA_SHIRQ))
+ desc->status |= IRQ_PENDING;
+ spin_unlock(&desc->lock);
+ continue;
+ }
+ /* Honour the normal IRQ locking */
+ desc->status |= IRQ_INPROGRESS;
+ spin_unlock(&desc->lock);
+ while (action) {
+ /* Only shared IRQ handlers are safe to call */
+ if (action->flags & SA_SHIRQ) {
+ if (action->handler(i, action->dev_id, regs) ==
+ IRQ_HANDLED)
+ ok = 1;
+ }
+ action = action->next;
+ }
+ local_irq_disable();
+ /* Now clean up the flags */
+ spin_lock(&desc->lock);
+ action = desc->action;
+
+ /*
+ * While we were looking for a fixup someone queued a real
+ * IRQ clashing with our walk
+ */
+
+ while ((desc->status & IRQ_PENDING) && action) {
+ /*
+ * Perform real IRQ processing for the IRQ we deferred
+ */
+ work = 1;
+ spin_unlock(&desc->lock);
+ handle_IRQ_event(i, regs, action);
+ spin_lock(&desc->lock);
+ desc->status &= ~IRQ_PENDING;
+ }
+ desc->status &= ~IRQ_INPROGRESS;
+ /*
+ * If we did actual work for the real IRQ line we must let the
+ * IRQ controller clean up too
+ */
+ if(work)
+ desc->handler->end(i);
+ spin_unlock(&desc->lock);
+ }
+ /* So the caller can adjust the irq error counts */
+ return ok;
+}
+
/*
* If 99,900 of the previous 100,000 interrupts have not been handled
* then assume that the IRQ is stuck in some manner. Drop a diagnostic
@@ -31,7 +108,8 @@ __report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
printk(KERN_ERR "irq event %d: bogus return value %x\n",
irq, action_ret);
} else {
- printk(KERN_ERR "irq %d: nobody cared!\n", irq);
+ printk(KERN_ERR "irq %d: nobody cared (try booting with "
+ "the \"irqpoll\" option)\n", irq);
}
dump_stack();
printk(KERN_ERR "handlers:\n");
@@ -45,7 +123,7 @@ __report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
}
}
-void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
+static void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
{
static int count = 100;
@@ -55,7 +133,8 @@ void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
}
}
-void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
+void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret,
+ struct pt_regs *regs)
{
if (action_ret != IRQ_HANDLED) {
desc->irqs_unhandled++;
@@ -63,6 +142,15 @@ void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
report_bad_irq(irq, desc, action_ret);
}
+ if (unlikely(irqfixup)) {
+ /* Don't punish working computers */
+ if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
+ int ok = misrouted_irq(irq, regs);
+ if (action_ret == IRQ_NONE)
+ desc->irqs_unhandled -= ok;
+ }
+ }
+
desc->irq_count++;
if (desc->irq_count < 100000)
return;
@@ -94,3 +182,24 @@ int __init noirqdebug_setup(char *str)
__setup("noirqdebug", noirqdebug_setup);
+static int __init irqfixup_setup(char *str)
+{
+ irqfixup = 1;
+ printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
+ printk(KERN_WARNING "This may impact system performance.\n");
+ return 1;
+}
+
+__setup("irqfixup", irqfixup_setup);
+
+static int __init irqpoll_setup(char *str)
+{
+ irqfixup = 2;
+ printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
+ "enabled\n");
+ printk(KERN_WARNING "This may significantly impact system "
+ "performance\n");
+ return 1;
+}
+
+__setup("irqpoll", irqpoll_setup);