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: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index d663338..5203a59 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -111,9 +111,9 @@
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 @@
}
desc = irq_desc + irq;
- if (desc->chip->set_type) {
- spin_lock_irqsave(&desc->lock, flags);
- ret = desc->chip->set_type(irq, type);
- spin_unlock_irqrestore(&desc->lock, flags);
- }
+ if (type == IRQ_TYPE_NONE)
+ return 0;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ ret = __irq_set_trigger(desc, irq, flags);
+ spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
EXPORT_SYMBOL(set_irq_type);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 08a849a..422dd00 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -10,6 +10,9 @@
/* 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);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d62f69b..e59157b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -216,7 +216,7 @@
}
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 @@
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 @@
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 @@
/* 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 @@
/* 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 @@
* 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,