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authorAlan Cox <alan@lxorguk.ukuu.org.uk>2005-06-28 23:45:18 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-29 00:20:35 -0400
commit200803dfe4ff772740d63db725ab2f1b185ccf92 (patch)
treef567852c984c947f792edb18fee273cfa363d374 /kernel/irq
parent21fe3471c3aaa5c489c5d3a4d705291eb7511248 (diff)
[PATCH] irqpoll
Anyone reporting a stuck IRQ should try these options. Its effectiveness varies we've found in the Fedora case. Quite a few systems with misdescribed IRQ routing just work when you use irqpoll. It also fixes up the VIA systems although thats now fixed with the VIA quirk (which we could just make default as its what Redmond OS does but Linus didn't like it historically). A small number of systems have jammed IRQ sources or misdescribes that cause an IRQ that we have no handler registered anywhere for. In those cases it doesn't help. Signed-off-by: Alan Cox <number6@the-village.bc.nu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/handle.c2
-rw-r--r--kernel/irq/spurious.c113
2 files changed, 112 insertions, 3 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 436c7d93c00a..c29f83c16497 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -172,7 +172,7 @@ fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
172 172
173 spin_lock(&desc->lock); 173 spin_lock(&desc->lock);
174 if (!noirqdebug) 174 if (!noirqdebug)
175 note_interrupt(irq, desc, action_ret); 175 note_interrupt(irq, desc, action_ret, regs);
176 if (likely(!(desc->status & IRQ_PENDING))) 176 if (likely(!(desc->status & IRQ_PENDING)))
177 break; 177 break;
178 desc->status &= ~IRQ_PENDING; 178 desc->status &= ~IRQ_PENDING;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index ba039e827d58..7df9abd5ec86 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -11,6 +11,83 @@
11#include <linux/kallsyms.h> 11#include <linux/kallsyms.h>
12#include <linux/interrupt.h> 12#include <linux/interrupt.h>
13 13
14static int irqfixup;
15
16/*
17 * Recovery handler for misrouted interrupts.
18 */
19
20static int misrouted_irq(int irq, struct pt_regs *regs)
21{
22 int i;
23 irq_desc_t *desc;
24 int ok = 0;
25 int work = 0; /* Did we do work for a real IRQ */
26
27 for(i = 1; i < NR_IRQS; i++) {
28 struct irqaction *action;
29
30 if (i == irq) /* Already tried */
31 continue;
32 desc = &irq_desc[i];
33 spin_lock(&desc->lock);
34 action = desc->action;
35 /* Already running on another processor */
36 if (desc->status & IRQ_INPROGRESS) {
37 /*
38 * Already running: If it is shared get the other
39 * CPU to go looking for our mystery interrupt too
40 */
41 if (desc->action && (desc->action->flags & SA_SHIRQ))
42 desc->status |= IRQ_PENDING;
43 spin_unlock(&desc->lock);
44 continue;
45 }
46 /* Honour the normal IRQ locking */
47 desc->status |= IRQ_INPROGRESS;
48 spin_unlock(&desc->lock);
49 while (action) {
50 /* Only shared IRQ handlers are safe to call */
51 if (action->flags & SA_SHIRQ) {
52 if (action->handler(i, action->dev_id, regs) ==
53 IRQ_HANDLED)
54 ok = 1;
55 }
56 action = action->next;
57 }
58 local_irq_disable();
59 /* Now clean up the flags */
60 spin_lock(&desc->lock);
61 action = desc->action;
62
63 /*
64 * While we were looking for a fixup someone queued a real
65 * IRQ clashing with our walk
66 */
67
68 while ((desc->status & IRQ_PENDING) && action) {
69 /*
70 * Perform real IRQ processing for the IRQ we deferred
71 */
72 work = 1;
73 spin_unlock(&desc->lock);
74 handle_IRQ_event(i, regs, action);
75 spin_lock(&desc->lock);
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 */
83 if(work)
84 desc->handler->end(i);
85 spin_unlock(&desc->lock);
86 }
87 /* So the caller can adjust the irq error counts */
88 return ok;
89}
90
14/* 91/*
15 * If 99,900 of the previous 100,000 interrupts have not been handled 92 * 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 93 * then assume that the IRQ is stuck in some manner. Drop a diagnostic
@@ -31,7 +108,8 @@ __report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
31 printk(KERN_ERR "irq event %d: bogus return value %x\n", 108 printk(KERN_ERR "irq event %d: bogus return value %x\n",
32 irq, action_ret); 109 irq, action_ret);
33 } else { 110 } else {
34 printk(KERN_ERR "irq %d: nobody cared!\n", irq); 111 printk(KERN_ERR "irq %d: nobody cared (try booting with "
112 "the \"irqpoll\" option)\n", irq);
35 } 113 }
36 dump_stack(); 114 dump_stack();
37 printk(KERN_ERR "handlers:\n"); 115 printk(KERN_ERR "handlers:\n");
@@ -55,7 +133,8 @@ static void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t actio
55 } 133 }
56} 134}
57 135
58void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret) 136void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret,
137 struct pt_regs *regs)
59{ 138{
60 if (action_ret != IRQ_HANDLED) { 139 if (action_ret != IRQ_HANDLED) {
61 desc->irqs_unhandled++; 140 desc->irqs_unhandled++;
@@ -63,6 +142,15 @@ void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
63 report_bad_irq(irq, desc, action_ret); 142 report_bad_irq(irq, desc, action_ret);
64 } 143 }
65 144
145 if (unlikely(irqfixup)) {
146 /* Don't punish working computers */
147 if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
148 int ok = misrouted_irq(irq, regs);
149 if (action_ret == IRQ_NONE)
150 desc->irqs_unhandled -= ok;
151 }
152 }
153
66 desc->irq_count++; 154 desc->irq_count++;
67 if (desc->irq_count < 100000) 155 if (desc->irq_count < 100000)
68 return; 156 return;
@@ -94,3 +182,24 @@ int __init noirqdebug_setup(char *str)
94 182
95__setup("noirqdebug", noirqdebug_setup); 183__setup("noirqdebug", noirqdebug_setup);
96 184
185static int __init irqfixup_setup(char *str)
186{
187 irqfixup = 1;
188 printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
189 printk(KERN_WARNING "This may impact system performance.\n");
190 return 1;
191}
192
193__setup("irqfixup", irqfixup_setup);
194
195static int __init irqpoll_setup(char *str)
196{
197 irqfixup = 2;
198 printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
199 "enabled\n");
200 printk(KERN_WARNING "This may significantly impact system "
201 "performance\n");
202 return 1;
203}
204
205__setup("irqpoll", irqpoll_setup);