Commit 0c5d1eb7 authored by David Brownell's avatar David Brownell Committed by Ingo Molnar
Browse files

genirq: record trigger type 



Genirq hasn't previously recorded the trigger type used by any given IRQ,
although some irq_chip support has done so.  That data can be useful when
troubleshooting.  This patch records it in the relevant irq_desc.status
bits, and improves consistency between the two driver-visible calls
affected:

 - Make set_irq_type() usage match request_irq() usage:
    * IRQ_TYPE_NONE should be a NOP; succeed, so irq_chip methods
      won't have to handle that case any more (many do it wrong).
    * IRQ_TYPE_PROBE is ignored; any buggy out-of-tree callers
      might need to switch over to the real IRQ probing code.
    * emit the same diagnostics (from shared utility code)

 - Their kerneldoc now reflects usage:
    * request_irq() flags include IRQF_TRIGGER_* to specify
      active edge(s)/level ... docs previously omitted that
    * set_irq_type() is declared in <linux/irq.h> so callers
      should use the (bit-equivalent) IRQ_TYPE_* symbols there

Also: adds a warning about shared IRQs that don't end up using the
requested trigger mode; and fix an unrelated "sparse" warning.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d6d5aeb6

kernel/irq/chip.c

+8 −7
Original line number Diff line number Diff line
@@ -111,9 +111,9 @@ int set_irq_chip(unsigned int irq, struct irq_chip *chip) 
EXPORT_SYMBOL(set_irq_chip);



/**

 *	set_irq_type - set the irq type for an irq

 *	set_irq_type - set the irq trigger type for an irq

 *	@irq:	irq number

 *	@type:	interrupt type - see include/linux/interrupt.h

 *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h

 */

int set_irq_type(unsigned int irq, unsigned int type)

{
@@ -127,11 +127,12 @@ int set_irq_type(unsigned int irq, unsigned int type) 
	}



	desc = irq_desc + irq;

	if (desc->chip->set_type) {

	if (type == IRQ_TYPE_NONE)

		return 0;



	spin_lock_irqsave(&desc->lock, flags);

		ret = desc->chip->set_type(irq, type);

	ret = __irq_set_trigger(desc, irq, flags);

	spin_unlock_irqrestore(&desc->lock, flags);

	}

	return ret;

}

EXPORT_SYMBOL(set_irq_type);

kernel/irq/internals.h

+3 −0
Original line number Diff line number Diff line
@@ -10,6 +10,9 @@ extern void irq_chip_set_defaults(struct irq_chip *chip); 
/* Set default handler: */

extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);



extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,

		unsigned long flags);



#ifdef CONFIG_PROC_FS

extern void register_irq_proc(unsigned int irq);

extern void register_handler_proc(unsigned int irq, struct irqaction *action);

kernel/irq/manage.c

+18 −3
Original line number Diff line number Diff line
@@ -216,7 +216,7 @@ void enable_irq(unsigned int irq) 
}

EXPORT_SYMBOL(enable_irq);



int set_irq_wake_real(unsigned int irq, unsigned int on)

static int set_irq_wake_real(unsigned int irq, unsigned int on)

{

	struct irq_desc *desc = irq_desc + irq;

	int ret = -ENXIO;
@@ -305,10 +305,11 @@ 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,

int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,

		unsigned long flags)

{

	int ret;

	struct irq_chip *chip = desc->chip;



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

		/*
@@ -326,6 +327,11 @@ static int __irq_set_trigger(struct irq_chip *chip, unsigned int irq, 
		pr_err("setting trigger mode %d for irq %u failed (%pF)\n",

				(int)(flags & IRQF_TRIGGER_MASK),

				irq, chip->set_type);

	else {

		/* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */

		desc->status &= ~IRQ_TYPE_SENSE_MASK;

		desc->status |= flags & IRQ_TYPE_SENSE_MASK;

	}



	return ret;

}
@@ -404,7 +410,7 @@ int setup_irq(unsigned int irq, struct irqaction *new) 


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

		if (new->flags & IRQF_TRIGGER_MASK) {

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

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



			if (ret) {

				spin_unlock_irqrestore(&desc->lock, flags);
@@ -430,6 +436,14 @@ int setup_irq(unsigned int irq, struct irqaction *new) 


		/* Set default affinity mask once everything is setup */

		irq_select_affinity(irq);



	} else if ((new->flags & IRQF_TRIGGER_MASK)

			&& (new->flags & IRQF_TRIGGER_MASK)

				!= (desc->status & IRQ_TYPE_SENSE_MASK)) {

		/* hope the handler works with the actual trigger mode... */

		pr_warning("IRQ %d uses trigger mode %d; requested %d\n",

				irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),

				(int)(new->flags & IRQF_TRIGGER_MASK));

	}



	*p = new;
@@ -586,6 +600,7 @@ EXPORT_SYMBOL(free_irq); 
 *	IRQF_SHARED		Interrupt is shared

 *	IRQF_DISABLED	Disable local interrupts while processing

 *	IRQF_SAMPLE_RANDOM	The interrupt can be used for entropy

 *	IRQF_TRIGGER_*		Specify active edge(s) or level

 *

 */

int request_irq(unsigned int irq, irq_handler_t handler,

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