Re: test for "spurious" IRQ ignores possible IRQ_WAKE_THREAD value

From: Robert P. J. Day
Date: Mon Sep 14 2009 - 16:34:56 EST


On Mon, 14 Sep 2009, Robert P. J. Day wrote:

> never ashamed to embarrass myself in public, i just noticed the
> following. from kernel/irq/spurious.c:
>
> ...
> static void
> __report_bad_irq(unsigned int irq, struct irq_desc *desc,
> irqreturn_t action_ret)
> {
> struct irqaction *action;
>
> if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
> printk(KERN_ERR "irq event %d: bogus return value %x\n",
> irq, action_ret);
>
> but from include/linux/irqreturn.h, we see *three* possible return
> values:
>
> enum irqreturn {
> IRQ_NONE,
> IRQ_HANDLED,
> IRQ_WAKE_THREAD,
> };
>
> typedef enum irqreturn irqreturn_t;
> #define IRQ_RETVAL(x) ((x) != IRQ_NONE)
>
> is there an inconsistency here?

i should have pointed out that there is (apparently) only one place
in the entire tree that uses that third return value:

$ grep -rw IRQ_WAKE_THREAD *
drivers/net/wireless/b43/main.c: return IRQ_WAKE_THREAD; <-- there
include/linux/irqreturn.h: * @IRQ_WAKE_THREAD handler requests to wake the handler thread
include/linux/irqreturn.h: IRQ_WAKE_THREAD,
Binary file include/linux/.irqreturn.h.swp matches
include/linux/interrupt.h: * IRQTF_WARNED - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
kernel/irq/handle.c: printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "
kernel/irq/handle.c: case IRQ_WAKE_THREAD:
kernel/irq/manage.c: return IRQ_WAKE_THREAD;
kernel/irq/manage.c: * IRQ_WAKE_THREAD which will wake up the handler thread and run
$

for what that's worth.

rday
--

========================================================================
Robert P. J. Day Waterloo, Ontario, CANADA

Linux Consulting, Training and Annoying Kernel Pedantry.

Web page: http://crashcourse.ca
Twitter: http://twitter.com/rpjday
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