diff mbox series

[01/23] kernel: irq: irqdescs: warn on spurious IRQ

Message ID 20201218143122.19459-2-info@metux.net (mailing list archive)
State New, archived
Headers show
Series [01/23] kernel: irq: irqdescs: warn on spurious IRQ | expand

Commit Message

Enrico Weigelt, metux IT consult Dec. 18, 2020, 2:31 p.m. UTC
Add a warning on spurious IRQs to __handle_domain_irq(), also telling the
linux IRQ number (if any), the hw IRQ number and the max nr of IRQs.

That's far more informative than the warnings in (some of) the individual
arch's ack_bad_irq()'s. These aren't really helpful since either the
other callers already had printed more detailed information or (when called
by __handle_domain_irq()) the printout just doesn't tell anything useful.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 kernel/irq/irqdesc.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Andy Shevchenko Dec. 18, 2020, 3:55 p.m. UTC | #1
On Fri, Dec 18, 2020 at 4:37 PM Enrico Weigelt, metux IT consult
<info@metux.net> wrote:

> +               if (printk_ratelimit())
> +                       pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
> +                               irq, hwirq, nr_irqs);

Perhaps you missed pr_warn_ratelimit() macro which is already in the
kernel for a long time.
Michael Ellerman Dec. 21, 2020, 5:44 a.m. UTC | #2
Andy Shevchenko <andy.shevchenko@gmail.com> writes:
> On Fri, Dec 18, 2020 at 4:37 PM Enrico Weigelt, metux IT consult
> <info@metux.net> wrote:
>
>> +               if (printk_ratelimit())
>> +                       pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
>> +                               irq, hwirq, nr_irqs);
>
> Perhaps you missed pr_warn_ratelimit() macro which is already in the
> kernel for a long time.

pr_warn_ratelimited() which calls printk_ratelimited().

And see the comment above printk_ratelimit():

/*
 * Please don't use printk_ratelimit(), because it shares ratelimiting state
 * with all other unrelated printk_ratelimit() callsites.  Instead use
 * printk_ratelimited() or plain old __ratelimit().
 */


cheers
Andy Shevchenko Dec. 21, 2020, 9:27 a.m. UTC | #3
On Mon, Dec 21, 2020 at 7:44 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
> Andy Shevchenko <andy.shevchenko@gmail.com> writes:
> > On Fri, Dec 18, 2020 at 4:37 PM Enrico Weigelt, metux IT consult
> > <info@metux.net> wrote:
> >
> >> +               if (printk_ratelimit())
> >> +                       pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
> >> +                               irq, hwirq, nr_irqs);
> >
> > Perhaps you missed pr_warn_ratelimit() macro which is already in the
> > kernel for a long time.
>
> pr_warn_ratelimited() which calls printk_ratelimited().

I stand corrected.
Right, that's what I had in mind (actually didn't know that there are variants).

Thanks!

> And see the comment above printk_ratelimit():
>
> /*
>  * Please don't use printk_ratelimit(), because it shares ratelimiting state
>  * with all other unrelated printk_ratelimit() callsites.  Instead use
>  * printk_ratelimited() or plain old __ratelimit().
>  */
diff mbox series

Patch

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index e810eb9906ea..62a381351775 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -681,6 +681,9 @@  int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 	 * than crashing, do something sensible.
 	 */
 	if (unlikely(!irq || irq >= nr_irqs)) {
+		if (printk_ratelimit())
+			pr_warn("spurious IRQ: irq=%d hwirq=%d nr_irqs=%d\n",
+				irq, hwirq, nr_irqs);
 		ack_bad_irq(irq);
 		ret = -EINVAL;
 	} else {