kernel/irq/spurious.c

   1 /*
   2  * linux/kernel/irq/spurious.c
   3  *
   4  * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
   5  *
   6  * This file contains spurious interrupt handling.
   7  */
   8
   9 #include <linux/irq.h>
  10 #include <linux/module.h>
  11 #include <linux/kallsyms.h>
  12 #include <linux/interrupt.h>
  13
  14 /*
  15  * If 99,900 of the previous 100,000 interrupts have not been handled
  16  * then assume that the IRQ is stuck in some manner. Drop a diagnostic
  17  * and try to turn the IRQ off.
  18  *
  19  * (The other 100-of-100,000 interrupts may have been a correctly
  20  *  functioning device sharing an IRQ with the failing one)
  21  *
  22  * Called under desc->lock
  23  */
  24
  25 static void
  26 __report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
  27 {
  28         struct irqaction *action;
  29
  30         if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
  31                 printk(KERN_ERR "irq event %d: bogus return value %x\n",
  32                                 irq, action_ret);
  33         } else {
  34                 printk(KERN_ERR "irq %d: nobody cared!\n", irq);
  35         }
  36         dump_stack();
  37         printk(KERN_ERR "handlers:\n");
  38         action = desc->action;
  39         while (action) {
  40                 printk(KERN_ERR "[<%p>]", action->handler);
  41                 print_symbol(" (%s)",
  42                         (unsigned long)action->handler);
  43                 printk("\n");
  44                 action = action->next;
  45         }
  46 }
  47
  48 void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
  49 {
  50         static int count = 100;
  51
  52         if (count > 0) {
  53                 count--;
  54                 __report_bad_irq(irq, desc, action_ret);
  55         }
  56 }
  57
  58 void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
  59 {
  60         if (action_ret != IRQ_HANDLED) {
  61                 desc->irqs_unhandled++;
  62                 if (action_ret != IRQ_NONE)
  63                         report_bad_irq(irq, desc, action_ret);
  64         }
  65
  66         desc->irq_count++;
  67         if (desc->irq_count < 100000)
  68                 return;
  69
  70         desc->irq_count = 0;
  71         if (desc->irqs_unhandled > 99900) {
  72                 /*
  73                  * The interrupt is stuck
  74                  */
  75                 __report_bad_irq(irq, desc, action_ret);
  76                 /*
  77                  * Now kill the IRQ
  78                  */
  79                 printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
  80                 desc->status |= IRQ_DISABLED;
  81                 desc->handler->disable(irq);
  82         }
  83         desc->irqs_unhandled = 0;
  84 }
  85
  86 int noirqdebug;
  87
  88 int __init noirqdebug_setup(char *str)
  89 {
  90         noirqdebug = 1;
  91         printk(KERN_INFO "IRQ lockup detection disabled\n");
  92         return 1;
  93 }
  94
  95 __setup("noirqdebug", noirqdebug_setup);
  96