Commit | Line | Data |
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1da177e4 LT |
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 | ||
188fd89d | 9 | #include <linux/jiffies.h> |
1da177e4 LT |
10 | #include <linux/irq.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/kallsyms.h> | |
13 | #include <linux/interrupt.h> | |
9e094c17 | 14 | #include <linux/moduleparam.h> |
f84dbb91 | 15 | #include <linux/timer.h> |
1da177e4 | 16 | |
83d4e6e7 | 17 | static int irqfixup __read_mostly; |
200803df | 18 | |
f84dbb91 EB |
19 | #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) |
20 | static void poll_spurious_irqs(unsigned long dummy); | |
21 | static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); | |
22 | ||
200803df AC |
23 | /* |
24 | * Recovery handler for misrouted interrupts. | |
25 | */ | |
f84dbb91 | 26 | static int try_one_irq(int irq, struct irq_desc *desc) |
200803df | 27 | { |
f84dbb91 | 28 | struct irqaction *action; |
d3c60047 | 29 | int ok = 0, work = 0; |
200803df | 30 | |
f84dbb91 EB |
31 | spin_lock(&desc->lock); |
32 | /* Already running on another processor */ | |
33 | if (desc->status & IRQ_INPROGRESS) { | |
34 | /* | |
35 | * Already running: If it is shared get the other | |
36 | * CPU to go looking for our mystery interrupt too | |
37 | */ | |
38 | if (desc->action && (desc->action->flags & IRQF_SHARED)) | |
39 | desc->status |= IRQ_PENDING; | |
200803df | 40 | spin_unlock(&desc->lock); |
f84dbb91 EB |
41 | return ok; |
42 | } | |
43 | /* Honour the normal IRQ locking */ | |
44 | desc->status |= IRQ_INPROGRESS; | |
45 | action = desc->action; | |
46 | spin_unlock(&desc->lock); | |
06fcb0c6 | 47 | |
f84dbb91 EB |
48 | while (action) { |
49 | /* Only shared IRQ handlers are safe to call */ | |
50 | if (action->flags & IRQF_SHARED) { | |
51 | if (action->handler(irq, action->dev_id) == | |
52 | IRQ_HANDLED) | |
53 | ok = 1; | |
200803df | 54 | } |
f84dbb91 EB |
55 | action = action->next; |
56 | } | |
57 | local_irq_disable(); | |
58 | /* Now clean up the flags */ | |
59 | spin_lock(&desc->lock); | |
60 | action = desc->action; | |
200803df | 61 | |
f84dbb91 EB |
62 | /* |
63 | * While we were looking for a fixup someone queued a real | |
64 | * IRQ clashing with our walk: | |
65 | */ | |
66 | while ((desc->status & IRQ_PENDING) && action) { | |
200803df | 67 | /* |
f84dbb91 | 68 | * Perform real IRQ processing for the IRQ we deferred |
200803df | 69 | */ |
f84dbb91 | 70 | work = 1; |
200803df | 71 | spin_unlock(&desc->lock); |
f84dbb91 EB |
72 | handle_IRQ_event(irq, action); |
73 | spin_lock(&desc->lock); | |
74 | desc->status &= ~IRQ_PENDING; | |
75 | } | |
76 | desc->status &= ~IRQ_INPROGRESS; | |
77 | /* | |
78 | * If we did actual work for the real IRQ line we must let the | |
79 | * IRQ controller clean up too | |
80 | */ | |
81 | if (work && desc->chip && desc->chip->end) | |
82 | desc->chip->end(irq); | |
83 | spin_unlock(&desc->lock); | |
84 | ||
85 | return ok; | |
86 | } | |
87 | ||
88 | static int misrouted_irq(int irq) | |
89 | { | |
e00585bb | 90 | struct irq_desc *desc; |
d3c60047 | 91 | int i, ok = 0; |
f84dbb91 | 92 | |
e00585bb | 93 | for_each_irq_desc(i, desc) { |
0b8f1efa YL |
94 | if (!desc) |
95 | continue; | |
96 | ||
e00585bb YL |
97 | if (!i) |
98 | continue; | |
f84dbb91 EB |
99 | |
100 | if (i == irq) /* Already tried */ | |
101 | continue; | |
102 | ||
103 | if (try_one_irq(i, desc)) | |
104 | ok = 1; | |
200803df AC |
105 | } |
106 | /* So the caller can adjust the irq error counts */ | |
107 | return ok; | |
108 | } | |
109 | ||
f84dbb91 EB |
110 | static void poll_spurious_irqs(unsigned long dummy) |
111 | { | |
e00585bb | 112 | struct irq_desc *desc; |
d3c60047 | 113 | int i; |
e00585bb YL |
114 | |
115 | for_each_irq_desc(i, desc) { | |
f84dbb91 EB |
116 | unsigned int status; |
117 | ||
0b8f1efa YL |
118 | if (!desc) |
119 | continue; | |
e00585bb YL |
120 | if (!i) |
121 | continue; | |
122 | ||
f84dbb91 EB |
123 | /* Racy but it doesn't matter */ |
124 | status = desc->status; | |
125 | barrier(); | |
126 | if (!(status & IRQ_SPURIOUS_DISABLED)) | |
127 | continue; | |
128 | ||
129 | try_one_irq(i, desc); | |
130 | } | |
131 | ||
d3c60047 TG |
132 | mod_timer(&poll_spurious_irq_timer, |
133 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
f84dbb91 EB |
134 | } |
135 | ||
1da177e4 LT |
136 | /* |
137 | * If 99,900 of the previous 100,000 interrupts have not been handled | |
138 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic | |
139 | * and try to turn the IRQ off. | |
140 | * | |
141 | * (The other 100-of-100,000 interrupts may have been a correctly | |
142 | * functioning device sharing an IRQ with the failing one) | |
143 | * | |
144 | * Called under desc->lock | |
145 | */ | |
146 | ||
147 | static void | |
34ffdb72 IM |
148 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
149 | irqreturn_t action_ret) | |
1da177e4 LT |
150 | { |
151 | struct irqaction *action; | |
152 | ||
153 | if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { | |
154 | printk(KERN_ERR "irq event %d: bogus return value %x\n", | |
155 | irq, action_ret); | |
156 | } else { | |
200803df AC |
157 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
158 | "the \"irqpoll\" option)\n", irq); | |
1da177e4 LT |
159 | } |
160 | dump_stack(); | |
161 | printk(KERN_ERR "handlers:\n"); | |
06fcb0c6 | 162 | |
1da177e4 LT |
163 | action = desc->action; |
164 | while (action) { | |
165 | printk(KERN_ERR "[<%p>]", action->handler); | |
166 | print_symbol(" (%s)", | |
167 | (unsigned long)action->handler); | |
168 | printk("\n"); | |
169 | action = action->next; | |
170 | } | |
171 | } | |
172 | ||
06fcb0c6 | 173 | static void |
34ffdb72 | 174 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
1da177e4 LT |
175 | { |
176 | static int count = 100; | |
177 | ||
178 | if (count > 0) { | |
179 | count--; | |
180 | __report_bad_irq(irq, desc, action_ret); | |
181 | } | |
182 | } | |
183 | ||
d3c60047 TG |
184 | static inline int |
185 | try_misrouted_irq(unsigned int irq, struct irq_desc *desc, | |
186 | irqreturn_t action_ret) | |
92ea7727 LT |
187 | { |
188 | struct irqaction *action; | |
189 | ||
190 | if (!irqfixup) | |
191 | return 0; | |
192 | ||
193 | /* We didn't actually handle the IRQ - see if it was misrouted? */ | |
194 | if (action_ret == IRQ_NONE) | |
195 | return 1; | |
196 | ||
197 | /* | |
198 | * But for 'irqfixup == 2' we also do it for handled interrupts if | |
199 | * they are marked as IRQF_IRQPOLL (or for irq zero, which is the | |
200 | * traditional PC timer interrupt.. Legacy) | |
201 | */ | |
202 | if (irqfixup < 2) | |
203 | return 0; | |
204 | ||
205 | if (!irq) | |
206 | return 1; | |
207 | ||
208 | /* | |
209 | * Since we don't get the descriptor lock, "action" can | |
210 | * change under us. We don't really care, but we don't | |
211 | * want to follow a NULL pointer. So tell the compiler to | |
212 | * just load it once by using a barrier. | |
213 | */ | |
214 | action = desc->action; | |
215 | barrier(); | |
216 | return action && (action->flags & IRQF_IRQPOLL); | |
217 | } | |
218 | ||
34ffdb72 | 219 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
7d12e780 | 220 | irqreturn_t action_ret) |
1da177e4 | 221 | { |
83d4e6e7 | 222 | if (unlikely(action_ret != IRQ_HANDLED)) { |
4f27c00b AC |
223 | /* |
224 | * If we are seeing only the odd spurious IRQ caused by | |
225 | * bus asynchronicity then don't eventually trigger an error, | |
226 | * otherwise the couter becomes a doomsday timer for otherwise | |
227 | * working systems | |
228 | */ | |
188fd89d | 229 | if (time_after(jiffies, desc->last_unhandled + HZ/10)) |
4f27c00b AC |
230 | desc->irqs_unhandled = 1; |
231 | else | |
232 | desc->irqs_unhandled++; | |
233 | desc->last_unhandled = jiffies; | |
83d4e6e7 | 234 | if (unlikely(action_ret != IRQ_NONE)) |
1da177e4 LT |
235 | report_bad_irq(irq, desc, action_ret); |
236 | } | |
237 | ||
92ea7727 LT |
238 | if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { |
239 | int ok = misrouted_irq(irq); | |
240 | if (action_ret == IRQ_NONE) | |
241 | desc->irqs_unhandled -= ok; | |
200803df AC |
242 | } |
243 | ||
1da177e4 | 244 | desc->irq_count++; |
83d4e6e7 | 245 | if (likely(desc->irq_count < 100000)) |
1da177e4 LT |
246 | return; |
247 | ||
248 | desc->irq_count = 0; | |
83d4e6e7 | 249 | if (unlikely(desc->irqs_unhandled > 99900)) { |
1da177e4 LT |
250 | /* |
251 | * The interrupt is stuck | |
252 | */ | |
253 | __report_bad_irq(irq, desc, action_ret); | |
254 | /* | |
255 | * Now kill the IRQ | |
256 | */ | |
257 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); | |
1adb0850 TG |
258 | desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; |
259 | desc->depth++; | |
d1bef4ed | 260 | desc->chip->disable(irq); |
f84dbb91 | 261 | |
d3c60047 TG |
262 | mod_timer(&poll_spurious_irq_timer, |
263 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
1da177e4 LT |
264 | } |
265 | desc->irqs_unhandled = 0; | |
266 | } | |
267 | ||
83d4e6e7 | 268 | int noirqdebug __read_mostly; |
1da177e4 | 269 | |
343cde51 | 270 | int noirqdebug_setup(char *str) |
1da177e4 LT |
271 | { |
272 | noirqdebug = 1; | |
273 | printk(KERN_INFO "IRQ lockup detection disabled\n"); | |
06fcb0c6 | 274 | |
1da177e4 LT |
275 | return 1; |
276 | } | |
277 | ||
278 | __setup("noirqdebug", noirqdebug_setup); | |
9e094c17 AK |
279 | module_param(noirqdebug, bool, 0644); |
280 | MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); | |
1da177e4 | 281 | |
200803df AC |
282 | static int __init irqfixup_setup(char *str) |
283 | { | |
284 | irqfixup = 1; | |
285 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); | |
286 | printk(KERN_WARNING "This may impact system performance.\n"); | |
06fcb0c6 | 287 | |
200803df AC |
288 | return 1; |
289 | } | |
290 | ||
291 | __setup("irqfixup", irqfixup_setup); | |
9e094c17 | 292 | module_param(irqfixup, int, 0644); |
e00585bb | 293 | MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode, 2: irqpoll mode"); |
200803df AC |
294 | |
295 | static int __init irqpoll_setup(char *str) | |
296 | { | |
297 | irqfixup = 2; | |
298 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " | |
299 | "enabled\n"); | |
300 | printk(KERN_WARNING "This may significantly impact system " | |
301 | "performance\n"); | |
302 | return 1; | |
303 | } | |
304 | ||
305 | __setup("irqpoll", irqpoll_setup); |