1 | /* |
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2 | * linux/kernel/irq/spurious.c |
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3 | * |
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4 | * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar |
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5 | * |
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6 | * This file contains spurious interrupt handling. |
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7 | */ |
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8 | |
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9 | #include <linux/irq.h> |
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10 | #include <linux/module.h> |
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11 | #include <linux/kallsyms.h> |
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12 | #include <linux/interrupt.h> |
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13 | |
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14 | static int irqfixup __read_mostly; |
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15 | |
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16 | /* |
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17 | * Recovery handler for misrouted interrupts. |
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18 | */ |
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19 | static int misrouted_irq(int irq, struct pt_regs *regs) |
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20 | { |
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21 | int i; |
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22 | int ok = 0; |
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23 | int work = 0; /* Did we do work for a real IRQ */ |
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24 | |
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25 | for (i = 1; i < NR_IRQS; i++) { |
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26 | struct irq_desc *desc = irq_desc + i; |
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27 | struct irqaction *action; |
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28 | |
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29 | if (i == irq) /* Already tried */ |
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30 | continue; |
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31 | |
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32 | spin_lock(&desc->lock); |
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33 | /* Already running on another processor */ |
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34 | if (desc->status & IRQ_INPROGRESS) { |
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35 | /* |
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36 | * Already running: If it is shared get the other |
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37 | * CPU to go looking for our mystery interrupt too |
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38 | */ |
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39 | if (desc->action && (desc->action->flags & IRQF_SHARED)) |
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40 | desc->status |= IRQ_PENDING; |
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41 | spin_unlock(&desc->lock); |
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42 | continue; |
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43 | } |
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44 | /* Honour the normal IRQ locking */ |
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45 | desc->status |= IRQ_INPROGRESS; |
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46 | action = desc->action; |
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47 | spin_unlock(&desc->lock); |
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48 | |
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49 | while (action) { |
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50 | /* Only shared IRQ handlers are safe to call */ |
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51 | if (action->flags & IRQF_SHARED) { |
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52 | if (action->handler(i, action->dev_id, regs) == |
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53 | IRQ_HANDLED) |
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54 | ok = 1; |
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55 | } |
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56 | action = action->next; |
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57 | } |
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58 | local_irq_disable(); |
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59 | /* Now clean up the flags */ |
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60 | spin_lock(&desc->lock); |
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61 | action = desc->action; |
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62 | |
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63 | /* |
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64 | * While we were looking for a fixup someone queued a real |
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65 | * IRQ clashing with our walk: |
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66 | */ |
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67 | while ((desc->status & IRQ_PENDING) && action) { |
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68 | /* |
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69 | * Perform real IRQ processing for the IRQ we deferred |
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70 | */ |
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71 | work = 1; |
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72 | spin_unlock(&desc->lock); |
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73 | handle_IRQ_event(i, regs, action); |
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74 | spin_lock(&desc->lock); |
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75 | desc->status &= ~IRQ_PENDING; |
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76 | } |
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77 | desc->status &= ~IRQ_INPROGRESS; |
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78 | /* |
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79 | * If we did actual work for the real IRQ line we must let the |
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80 | * IRQ controller clean up too |
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81 | */ |
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82 | if (work && desc->chip && desc->chip->end) |
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83 | desc->chip->end(i); |
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84 | spin_unlock(&desc->lock); |
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85 | } |
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86 | /* So the caller can adjust the irq error counts */ |
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87 | return ok; |
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88 | } |
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89 | |
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90 | /* |
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91 | * If 99,900 of the previous 100,000 interrupts have not been handled |
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92 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic |
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93 | * and try to turn the IRQ off. |
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94 | * |
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95 | * (The other 100-of-100,000 interrupts may have been a correctly |
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96 | * functioning device sharing an IRQ with the failing one) |
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97 | * |
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98 | * Called under desc->lock |
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99 | */ |
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100 | |
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101 | static void |
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102 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
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103 | irqreturn_t action_ret) |
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104 | { |
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105 | struct irqaction *action; |
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106 | |
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107 | if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { |
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108 | printk(KERN_ERR "irq event %d: bogus return value %x\n", |
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109 | irq, action_ret); |
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110 | } else { |
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111 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
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112 | "the \"irqpoll\" option)\n", irq); |
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113 | } |
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114 | dump_stack(); |
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115 | printk(KERN_ERR "handlers:\n"); |
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116 | |
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117 | action = desc->action; |
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118 | while (action) { |
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119 | printk(KERN_ERR "[<%p>]", action->handler); |
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120 | print_symbol(" (%s)", |
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121 | (unsigned long)action->handler); |
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122 | printk("\n"); |
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123 | action = action->next; |
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124 | } |
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125 | } |
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126 | |
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127 | static void |
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128 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
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129 | { |
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130 | static int count = 100; |
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131 | |
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132 | if (count > 0) { |
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133 | count--; |
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134 | __report_bad_irq(irq, desc, action_ret); |
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135 | } |
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136 | } |
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137 | |
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138 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
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139 | irqreturn_t action_ret, struct pt_regs *regs) |
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140 | { |
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141 | if (unlikely(action_ret != IRQ_HANDLED)) { |
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142 | if (!irq_ignore_unhandled(irq)) |
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143 | desc->irqs_unhandled++; |
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144 | if (unlikely(action_ret != IRQ_NONE)) |
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145 | report_bad_irq(irq, desc, action_ret); |
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146 | } |
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147 | |
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148 | if (unlikely(irqfixup)) { |
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149 | /* Don't punish working computers */ |
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150 | if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) { |
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151 | int ok = misrouted_irq(irq, regs); |
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152 | if (action_ret == IRQ_NONE) |
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153 | desc->irqs_unhandled -= ok; |
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154 | } |
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155 | } |
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156 | |
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157 | desc->irq_count++; |
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158 | if (likely(desc->irq_count < 100000)) |
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159 | return; |
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160 | |
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161 | desc->irq_count = 0; |
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162 | if (unlikely(desc->irqs_unhandled > 99900)) { |
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163 | /* |
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164 | * The interrupt is stuck |
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165 | */ |
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166 | __report_bad_irq(irq, desc, action_ret); |
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167 | /* |
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168 | * Now kill the IRQ |
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169 | */ |
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170 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); |
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171 | desc->status |= IRQ_DISABLED; |
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172 | desc->depth = 1; |
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173 | desc->chip->disable(irq); |
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174 | } |
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175 | desc->irqs_unhandled = 0; |
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176 | } |
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177 | |
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178 | int noirqdebug __read_mostly; |
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179 | |
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180 | int __init noirqdebug_setup(char *str) |
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181 | { |
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182 | noirqdebug = 1; |
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183 | printk(KERN_INFO "IRQ lockup detection disabled\n"); |
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184 | |
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185 | return 1; |
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186 | } |
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187 | |
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188 | __setup("noirqdebug", noirqdebug_setup); |
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189 | |
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190 | static int __init irqfixup_setup(char *str) |
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191 | { |
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192 | irqfixup = 1; |
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193 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); |
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194 | printk(KERN_WARNING "This may impact system performance.\n"); |
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195 | |
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196 | return 1; |
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197 | } |
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198 | |
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199 | __setup("irqfixup", irqfixup_setup); |
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200 | |
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201 | static int __init irqpoll_setup(char *str) |
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202 | { |
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203 | irqfixup = 2; |
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204 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " |
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205 | "enabled\n"); |
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206 | printk(KERN_WARNING "This may significantly impact system " |
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207 | "performance\n"); |
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208 | return 1; |
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209 | } |
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210 | |
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211 | __setup("irqpoll", irqpoll_setup); |
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