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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 | |
bd151412 TG |
17 | #include "internals.h" |
18 | ||
83d4e6e7 | 19 | static int irqfixup __read_mostly; |
200803df | 20 | |
f84dbb91 EB |
21 | #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) |
22 | static void poll_spurious_irqs(unsigned long dummy); | |
23 | static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); | |
24 | ||
200803df AC |
25 | /* |
26 | * Recovery handler for misrouted interrupts. | |
27 | */ | |
f84dbb91 | 28 | static int try_one_irq(int irq, struct irq_desc *desc) |
200803df | 29 | { |
f84dbb91 | 30 | struct irqaction *action; |
d3c60047 | 31 | int ok = 0, work = 0; |
200803df | 32 | |
239007b8 | 33 | raw_spin_lock(&desc->lock); |
f84dbb91 EB |
34 | /* Already running on another processor */ |
35 | if (desc->status & IRQ_INPROGRESS) { | |
36 | /* | |
37 | * Already running: If it is shared get the other | |
38 | * CPU to go looking for our mystery interrupt too | |
39 | */ | |
40 | if (desc->action && (desc->action->flags & IRQF_SHARED)) | |
41 | desc->status |= IRQ_PENDING; | |
239007b8 | 42 | raw_spin_unlock(&desc->lock); |
f84dbb91 EB |
43 | return ok; |
44 | } | |
45 | /* Honour the normal IRQ locking */ | |
46 | desc->status |= IRQ_INPROGRESS; | |
47 | action = desc->action; | |
239007b8 | 48 | raw_spin_unlock(&desc->lock); |
06fcb0c6 | 49 | |
f84dbb91 EB |
50 | while (action) { |
51 | /* Only shared IRQ handlers are safe to call */ | |
52 | if (action->flags & IRQF_SHARED) { | |
53 | if (action->handler(irq, action->dev_id) == | |
54 | IRQ_HANDLED) | |
55 | ok = 1; | |
200803df | 56 | } |
f84dbb91 EB |
57 | action = action->next; |
58 | } | |
59 | local_irq_disable(); | |
60 | /* Now clean up the flags */ | |
239007b8 | 61 | raw_spin_lock(&desc->lock); |
f84dbb91 | 62 | action = desc->action; |
200803df | 63 | |
f84dbb91 EB |
64 | /* |
65 | * While we were looking for a fixup someone queued a real | |
66 | * IRQ clashing with our walk: | |
67 | */ | |
68 | while ((desc->status & IRQ_PENDING) && action) { | |
200803df | 69 | /* |
f84dbb91 | 70 | * Perform real IRQ processing for the IRQ we deferred |
200803df | 71 | */ |
f84dbb91 | 72 | work = 1; |
239007b8 | 73 | raw_spin_unlock(&desc->lock); |
f84dbb91 | 74 | handle_IRQ_event(irq, action); |
239007b8 | 75 | raw_spin_lock(&desc->lock); |
f84dbb91 EB |
76 | desc->status &= ~IRQ_PENDING; |
77 | } | |
78 | desc->status &= ~IRQ_INPROGRESS; | |
79 | /* | |
80 | * If we did actual work for the real IRQ line we must let the | |
81 | * IRQ controller clean up too | |
82 | */ | |
bd151412 TG |
83 | if (work) |
84 | irq_end(irq, desc); | |
239007b8 | 85 | raw_spin_unlock(&desc->lock); |
f84dbb91 EB |
86 | |
87 | return ok; | |
88 | } | |
89 | ||
90 | static int misrouted_irq(int irq) | |
91 | { | |
e00585bb | 92 | struct irq_desc *desc; |
d3c60047 | 93 | int i, ok = 0; |
f84dbb91 | 94 | |
e00585bb YL |
95 | for_each_irq_desc(i, desc) { |
96 | if (!i) | |
97 | continue; | |
f84dbb91 EB |
98 | |
99 | if (i == irq) /* Already tried */ | |
100 | continue; | |
101 | ||
102 | if (try_one_irq(i, desc)) | |
103 | ok = 1; | |
200803df AC |
104 | } |
105 | /* So the caller can adjust the irq error counts */ | |
106 | return ok; | |
107 | } | |
108 | ||
663e6959 | 109 | static void poll_spurious_irqs(unsigned long dummy) |
f84dbb91 | 110 | { |
e00585bb | 111 | struct irq_desc *desc; |
d3c60047 | 112 | int i; |
e00585bb YL |
113 | |
114 | for_each_irq_desc(i, desc) { | |
f84dbb91 EB |
115 | unsigned int status; |
116 | ||
e00585bb YL |
117 | if (!i) |
118 | continue; | |
119 | ||
f84dbb91 EB |
120 | /* Racy but it doesn't matter */ |
121 | status = desc->status; | |
122 | barrier(); | |
123 | if (!(status & IRQ_SPURIOUS_DISABLED)) | |
124 | continue; | |
125 | ||
e7e7e0c0 | 126 | local_irq_disable(); |
f84dbb91 | 127 | try_one_irq(i, desc); |
e7e7e0c0 | 128 | local_irq_enable(); |
f84dbb91 EB |
129 | } |
130 | ||
d3c60047 TG |
131 | mod_timer(&poll_spurious_irq_timer, |
132 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
f84dbb91 EB |
133 | } |
134 | ||
1da177e4 LT |
135 | /* |
136 | * If 99,900 of the previous 100,000 interrupts have not been handled | |
137 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic | |
138 | * and try to turn the IRQ off. | |
139 | * | |
140 | * (The other 100-of-100,000 interrupts may have been a correctly | |
141 | * functioning device sharing an IRQ with the failing one) | |
142 | * | |
143 | * Called under desc->lock | |
144 | */ | |
145 | ||
146 | static void | |
34ffdb72 IM |
147 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
148 | irqreturn_t action_ret) | |
1da177e4 LT |
149 | { |
150 | struct irqaction *action; | |
151 | ||
152 | if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { | |
153 | printk(KERN_ERR "irq event %d: bogus return value %x\n", | |
154 | irq, action_ret); | |
155 | } else { | |
200803df AC |
156 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
157 | "the \"irqpoll\" option)\n", irq); | |
1da177e4 LT |
158 | } |
159 | dump_stack(); | |
160 | printk(KERN_ERR "handlers:\n"); | |
06fcb0c6 | 161 | |
1da177e4 LT |
162 | action = desc->action; |
163 | while (action) { | |
164 | printk(KERN_ERR "[<%p>]", action->handler); | |
165 | print_symbol(" (%s)", | |
166 | (unsigned long)action->handler); | |
167 | printk("\n"); | |
168 | action = action->next; | |
169 | } | |
170 | } | |
171 | ||
06fcb0c6 | 172 | static void |
34ffdb72 | 173 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
1da177e4 LT |
174 | { |
175 | static int count = 100; | |
176 | ||
177 | if (count > 0) { | |
178 | count--; | |
179 | __report_bad_irq(irq, desc, action_ret); | |
180 | } | |
181 | } | |
182 | ||
d3c60047 TG |
183 | static inline int |
184 | try_misrouted_irq(unsigned int irq, struct irq_desc *desc, | |
185 | irqreturn_t action_ret) | |
92ea7727 LT |
186 | { |
187 | struct irqaction *action; | |
188 | ||
189 | if (!irqfixup) | |
190 | return 0; | |
191 | ||
192 | /* We didn't actually handle the IRQ - see if it was misrouted? */ | |
193 | if (action_ret == IRQ_NONE) | |
194 | return 1; | |
195 | ||
196 | /* | |
197 | * But for 'irqfixup == 2' we also do it for handled interrupts if | |
198 | * they are marked as IRQF_IRQPOLL (or for irq zero, which is the | |
199 | * traditional PC timer interrupt.. Legacy) | |
200 | */ | |
201 | if (irqfixup < 2) | |
202 | return 0; | |
203 | ||
204 | if (!irq) | |
205 | return 1; | |
206 | ||
207 | /* | |
208 | * Since we don't get the descriptor lock, "action" can | |
209 | * change under us. We don't really care, but we don't | |
210 | * want to follow a NULL pointer. So tell the compiler to | |
211 | * just load it once by using a barrier. | |
212 | */ | |
213 | action = desc->action; | |
214 | barrier(); | |
215 | return action && (action->flags & IRQF_IRQPOLL); | |
216 | } | |
217 | ||
34ffdb72 | 218 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
7d12e780 | 219 | irqreturn_t action_ret) |
1da177e4 | 220 | { |
83d4e6e7 | 221 | if (unlikely(action_ret != IRQ_HANDLED)) { |
4f27c00b AC |
222 | /* |
223 | * If we are seeing only the odd spurious IRQ caused by | |
224 | * bus asynchronicity then don't eventually trigger an error, | |
fbfecd37 | 225 | * otherwise the counter becomes a doomsday timer for otherwise |
4f27c00b AC |
226 | * working systems |
227 | */ | |
188fd89d | 228 | if (time_after(jiffies, desc->last_unhandled + HZ/10)) |
4f27c00b AC |
229 | desc->irqs_unhandled = 1; |
230 | else | |
231 | desc->irqs_unhandled++; | |
232 | desc->last_unhandled = jiffies; | |
83d4e6e7 | 233 | if (unlikely(action_ret != IRQ_NONE)) |
1da177e4 LT |
234 | report_bad_irq(irq, desc, action_ret); |
235 | } | |
236 | ||
92ea7727 LT |
237 | if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { |
238 | int ok = misrouted_irq(irq); | |
239 | if (action_ret == IRQ_NONE) | |
240 | desc->irqs_unhandled -= ok; | |
200803df AC |
241 | } |
242 | ||
1da177e4 | 243 | desc->irq_count++; |
83d4e6e7 | 244 | if (likely(desc->irq_count < 100000)) |
1da177e4 LT |
245 | return; |
246 | ||
247 | desc->irq_count = 0; | |
83d4e6e7 | 248 | if (unlikely(desc->irqs_unhandled > 99900)) { |
1da177e4 LT |
249 | /* |
250 | * The interrupt is stuck | |
251 | */ | |
252 | __report_bad_irq(irq, desc, action_ret); | |
253 | /* | |
254 | * Now kill the IRQ | |
255 | */ | |
256 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); | |
1adb0850 TG |
257 | desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; |
258 | desc->depth++; | |
bc310dda | 259 | desc->irq_data.chip->irq_disable(&desc->irq_data); |
f84dbb91 | 260 | |
d3c60047 TG |
261 | mod_timer(&poll_spurious_irq_timer, |
262 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
1da177e4 LT |
263 | } |
264 | desc->irqs_unhandled = 0; | |
265 | } | |
266 | ||
83d4e6e7 | 267 | int noirqdebug __read_mostly; |
1da177e4 | 268 | |
343cde51 | 269 | int noirqdebug_setup(char *str) |
1da177e4 LT |
270 | { |
271 | noirqdebug = 1; | |
272 | printk(KERN_INFO "IRQ lockup detection disabled\n"); | |
06fcb0c6 | 273 | |
1da177e4 LT |
274 | return 1; |
275 | } | |
276 | ||
277 | __setup("noirqdebug", noirqdebug_setup); | |
9e094c17 AK |
278 | module_param(noirqdebug, bool, 0644); |
279 | MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); | |
1da177e4 | 280 | |
200803df AC |
281 | static int __init irqfixup_setup(char *str) |
282 | { | |
283 | irqfixup = 1; | |
284 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); | |
285 | printk(KERN_WARNING "This may impact system performance.\n"); | |
06fcb0c6 | 286 | |
200803df AC |
287 | return 1; |
288 | } | |
289 | ||
290 | __setup("irqfixup", irqfixup_setup); | |
9e094c17 | 291 | module_param(irqfixup, int, 0644); |
200803df AC |
292 | |
293 | static int __init irqpoll_setup(char *str) | |
294 | { | |
295 | irqfixup = 2; | |
296 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " | |
297 | "enabled\n"); | |
298 | printk(KERN_WARNING "This may significantly impact system " | |
299 | "performance\n"); | |
300 | return 1; | |
301 | } | |
302 | ||
303 | __setup("irqpoll", irqpoll_setup); |