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 <<<<<<< HEAD:kernel/irq/spurious.c
  10 =======
  11 #include <linux/jiffies.h>
  12 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:kernel/irq/spurious.c
  13 #include <linux/irq.h>
  14 #include <linux/module.h>
  15 #include <linux/kallsyms.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/moduleparam.h>
  18
  19 static int irqfixup __read_mostly;
  20
  21 /*
  22  * Recovery handler for misrouted interrupts.
  23  */
  24 static int misrouted_irq(int irq)
  25 {
  26         int i;
  27         int ok = 0;
  28         int work = 0;   /* Did we do work for a real IRQ */
  29
  30         for (i = 1; i < NR_IRQS; i++) {
  31                 struct irq_desc *desc = irq_desc + i;
  32                 struct irqaction *action;
  33
  34                 if (i == irq)   /* Already tried */
  35                         continue;
  36
  37                 spin_lock(&desc->lock);
  38                 /* Already running on another processor */
  39                 if (desc->status & IRQ_INPROGRESS) {
  40                         /*
  41                          * Already running: If it is shared get the other
  42                          * CPU to go looking for our mystery interrupt too
  43                          */
  44                         if (desc->action && (desc->action->flags & IRQF_SHARED))
  45                                 desc->status |= IRQ_PENDING;
  46                         spin_unlock(&desc->lock);
  47                         continue;
  48                 }
  49                 /* Honour the normal IRQ locking */
  50                 desc->status |= IRQ_INPROGRESS;
  51                 action = desc->action;
  52                 spin_unlock(&desc->lock);
  53
  54                 while (action) {
  55                         /* Only shared IRQ handlers are safe to call */
  56                         if (action->flags & IRQF_SHARED) {
  57                                 if (action->handler(i, action->dev_id) ==
  58                                                 IRQ_HANDLED)
  59                                         ok = 1;
  60                         }
  61                         action = action->next;
  62                 }
  63                 local_irq_disable();
  64                 /* Now clean up the flags */
  65                 spin_lock(&desc->lock);
  66                 action = desc->action;
  67
  68                 /*
  69                  * While we were looking for a fixup someone queued a real
  70                  * IRQ clashing with our walk:
  71                  */
  72                 while ((desc->status & IRQ_PENDING) && action) {
  73                         /*
  74                          * Perform real IRQ processing for the IRQ we deferred
  75                          */
  76                         work = 1;
  77                         spin_unlock(&desc->lock);
  78                         handle_IRQ_event(i, action);
  79                         spin_lock(&desc->lock);
  80                         desc->status &= ~IRQ_PENDING;
  81                 }
  82                 desc->status &= ~IRQ_INPROGRESS;
  83                 /*
  84                  * If we did actual work for the real IRQ line we must let the
  85                  * IRQ controller clean up too
  86                  */
  87                 if (work && desc->chip && desc->chip->end)
  88                         desc->chip->end(i);
  89                 spin_unlock(&desc->lock);
  90         }
  91         /* So the caller can adjust the irq error counts */
  92         return ok;
  93 }
  94
  95 /*
  96  * If 99,900 of the previous 100,000 interrupts have not been handled
  97  * then assume that the IRQ is stuck in some manner. Drop a diagnostic
  98  * and try to turn the IRQ off.
  99  *
 100  * (The other 100-of-100,000 interrupts may have been a correctly
 101  *  functioning device sharing an IRQ with the failing one)
 102  *
 103  * Called under desc->lock
 104  */
 105
 106 static void
 107 __report_bad_irq(unsigned int irq, struct irq_desc *desc,
 108                  irqreturn_t action_ret)
 109 {
 110         struct irqaction *action;
 111
 112         if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
 113                 printk(KERN_ERR "irq event %d: bogus return value %x\n",
 114                                 irq, action_ret);
 115         } else {
 116                 printk(KERN_ERR "irq %d: nobody cared (try booting with "
 117                                 "the \"irqpoll\" option)\n", irq);
 118         }
 119         dump_stack();
 120         printk(KERN_ERR "handlers:\n");
 121
 122         action = desc->action;
 123         while (action) {
 124                 printk(KERN_ERR "[<%p>]", action->handler);
 125                 print_symbol(" (%s)",
 126                         (unsigned long)action->handler);
 127                 printk("\n");
 128                 action = action->next;
 129         }
 130 }
 131
 132 static void
 133 report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
 134 {
 135         static int count = 100;
 136
 137         if (count > 0) {
 138                 count--;
 139                 __report_bad_irq(irq, desc, action_ret);
 140         }
 141 }
 142
 143 static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
 144 {
 145         struct irqaction *action;
 146
 147         if (!irqfixup)
 148                 return 0;
 149
 150         /* We didn't actually handle the IRQ - see if it was misrouted? */
 151         if (action_ret == IRQ_NONE)
 152                 return 1;
 153
 154         /*
 155          * But for 'irqfixup == 2' we also do it for handled interrupts if
 156          * they are marked as IRQF_IRQPOLL (or for irq zero, which is the
 157          * traditional PC timer interrupt.. Legacy)
 158          */
 159         if (irqfixup < 2)
 160                 return 0;
 161
 162         if (!irq)
 163                 return 1;
 164
 165         /*
 166          * Since we don't get the descriptor lock, "action" can
 167          * change under us.  We don't really care, but we don't
 168          * want to follow a NULL pointer. So tell the compiler to
 169          * just load it once by using a barrier.
 170          */
 171         action = desc->action;
 172         barrier();
 173         return action && (action->flags & IRQF_IRQPOLL);
 174 }
 175
 176 void note_interrupt(unsigned int irq, struct irq_desc *desc,
 177                     irqreturn_t action_ret)
 178 {
 179         if (unlikely(action_ret != IRQ_HANDLED)) {
 180                 /*
 181                  * If we are seeing only the odd spurious IRQ caused by
 182                  * bus asynchronicity then don't eventually trigger an error,
 183                  * otherwise the couter becomes a doomsday timer for otherwise
 184                  * working systems
 185                  */
 186 <<<<<<< HEAD:kernel/irq/spurious.c
 187                 if (jiffies - desc->last_unhandled > HZ/10)
 188 =======
 189                 if (time_after(jiffies, desc->last_unhandled + HZ/10))
 190 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:kernel/irq/spurious.c
 191                         desc->irqs_unhandled = 1;
 192                 else
 193                         desc->irqs_unhandled++;
 194                 desc->last_unhandled = jiffies;
 195                 if (unlikely(action_ret != IRQ_NONE))
 196                         report_bad_irq(irq, desc, action_ret);
 197         }
 198
 199         if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
 200                 int ok = misrouted_irq(irq);
 201                 if (action_ret == IRQ_NONE)
 202                         desc->irqs_unhandled -= ok;
 203         }
 204
 205         desc->irq_count++;
 206         if (likely(desc->irq_count < 100000))
 207                 return;
 208
 209         desc->irq_count = 0;
 210         if (unlikely(desc->irqs_unhandled > 99900)) {
 211                 /*
 212                  * The interrupt is stuck
 213                  */
 214                 __report_bad_irq(irq, desc, action_ret);
 215                 /*
 216                  * Now kill the IRQ
 217                  */
 218                 printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
 219                 desc->status |= IRQ_DISABLED;
 220                 desc->depth = 1;
 221                 desc->chip->disable(irq);
 222         }
 223         desc->irqs_unhandled = 0;
 224 }
 225
 226 int noirqdebug __read_mostly;
 227
 228 int noirqdebug_setup(char *str)
 229 {
 230         noirqdebug = 1;
 231         printk(KERN_INFO "IRQ lockup detection disabled\n");
 232
 233         return 1;
 234 }
 235
 236 __setup("noirqdebug", noirqdebug_setup);
 237 module_param(noirqdebug, bool, 0644);
 238 MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true");
 239
 240 static int __init irqfixup_setup(char *str)
 241 {
 242         irqfixup = 1;
 243         printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 244         printk(KERN_WARNING "This may impact system performance.\n");
 245
 246         return 1;
 247 }
 248
 249 __setup("irqfixup", irqfixup_setup);
 250 module_param(irqfixup, int, 0644);
 251 MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode 2: irqpoll mode");
 252
 253 static int __init irqpoll_setup(char *str)
 254 {
 255         irqfixup = 2;
 256         printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 257                                 "enabled\n");
 258         printk(KERN_WARNING "This may significantly impact system "
 259                                 "performance\n");
 260         return 1;
 261 }
 262
 263 __setup("irqpoll", irqpoll_setup);