x86: add /proc/irq/*/spurious to dump the spurious irq debugging state
This is useful to debug problems with interrupt handlers that return
sometimes IRQ_NONE.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 50b81b9..c2f2ccb 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -75,6 +75,18 @@
#endif
+static int irq_spurious_read(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ struct irq_desc *d = &irq_desc[(long) data];
+ return sprintf(page, "count %u\n"
+ "unhandled %u\n"
+ "last_unhandled %u ms\n",
+ d->irq_count,
+ d->irqs_unhandled,
+ jiffies_to_msecs(d->last_unhandled));
+}
+
#define MAX_NAMELEN 128
static int name_unique(unsigned int irq, struct irqaction *new_action)
@@ -118,6 +130,7 @@
void register_irq_proc(unsigned int irq)
{
char name [MAX_NAMELEN];
+ struct proc_dir_entry *entry;
if (!root_irq_dir ||
(irq_desc[irq].chip == &no_irq_chip) ||
@@ -132,8 +145,6 @@
#ifdef CONFIG_SMP
{
- struct proc_dir_entry *entry;
-
/* create /proc/irq/<irq>/smp_affinity */
entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
@@ -144,6 +155,12 @@
}
}
#endif
+
+ entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir);
+ if (entry) {
+ entry->data = (void *)(long)irq;
+ entry->read_proc = irq_spurious_read;
+ }
}
#undef MAX_NAMELEN
