Commit 82736f4d authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Linus Torvalds
Browse files

generic irqs: handle failure of irqchip->set_type in setup_irq 



set_type returns an int indicating success or failure, but up to now
setup_irq ignores that.

In my case this resulted in a machine hang:

gpio-keys requested IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, but
arm/ns9xxx can only trigger on one direction so set_type didn't touch
the configuration which happens do default to a level sensitiveness and
returned -EINVAL.  setup_irq ignored that and unmasked the irq.  This
resulted in an endless triggering of the gpio-key interrupt service
routine which effectively killed the machine.

With this patch applied setup_irq propagates the error to the caller.

Note that before in the case

	chip && !chip->set_type && !chip->name

a NULL pointer was feed to printk.  This is fixed, too.

Signed-off-by: default avatarUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f606ddf4

kernel/irq/manage.c

+42 −22
Original line number Diff line number Diff line
@@ -308,6 +308,30 @@ void compat_irq_chip_set_default_handler(struct irq_desc *desc) 
		desc->handle_irq = NULL;

}



static int __irq_set_trigger(struct irq_chip *chip, unsigned int irq,

		unsigned long flags)

{

	int ret;



	if (!chip || !chip->set_type) {

		/*

		 * IRQF_TRIGGER_* but the PIC does not support multiple

		 * flow-types?

		 */

		pr_warning("No set_type function for IRQ %d (%s)\n", irq,

				chip ? (chip->name ? : "unknown") : "unknown");

		return 0;

	}



	ret = chip->set_type(irq, flags & IRQF_TRIGGER_MASK);



	if (ret)

		pr_err("setting flow type for irq %u failed (%pF)\n",

				irq, chip->set_type);



	return ret;

}



/*

 * Internal function to register an irqaction - typically used to

 * allocate special interrupts that are part of the architecture.
@@ -319,6 +343,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) 
	const char *old_name = NULL;

	unsigned long flags;

	int shared = 0;

	int ret;



	if (irq >= NR_IRQS)

		return -EINVAL;
@@ -376,35 +401,23 @@ int setup_irq(unsigned int irq, struct irqaction *new) 
		shared = 1;

	}



	*p = new;



	/* Exclude IRQ from balancing */

	if (new->flags & IRQF_NOBALANCING)

		desc->status |= IRQ_NO_BALANCING;



	if (!shared) {

		irq_chip_set_defaults(desc->chip);



#if defined(CONFIG_IRQ_PER_CPU)

		if (new->flags & IRQF_PERCPU)

			desc->status |= IRQ_PER_CPU;

#endif



		/* Setup the type (level, edge polarity) if configured: */

		if (new->flags & IRQF_TRIGGER_MASK) {

			if (desc->chip->set_type)

				desc->chip->set_type(irq,

						new->flags & IRQF_TRIGGER_MASK);

			else

				/*

				 * IRQF_TRIGGER_* but the PIC does not support

				 * multiple flow-types?

				 */

				printk(KERN_WARNING "No IRQF_TRIGGER set_type "

				       "function for IRQ %d (%s)\n", irq,

				       desc->chip->name);

			ret = __irq_set_trigger(desc->chip, irq, new->flags);



			if (ret) {

				spin_unlock_irqrestore(&desc->lock, flags);

				return ret;

			}

		} else

			compat_irq_chip_set_default_handler(desc);

#if defined(CONFIG_IRQ_PER_CPU)

		if (new->flags & IRQF_PERCPU)

			desc->status |= IRQ_PER_CPU;

#endif



		desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |

				  IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
@@ -423,6 +436,13 @@ int setup_irq(unsigned int irq, struct irqaction *new) 
		/* Set default affinity mask once everything is setup */

		irq_select_affinity(irq);

	}



	*p = new;



	/* Exclude IRQ from balancing */

	if (new->flags & IRQF_NOBALANCING)

		desc->status |= IRQ_NO_BALANCING;



	/* Reset broken irq detection when installing new handler */

	desc->irq_count = 0;

	desc->irqs_unhandled = 0;

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