[patch V2 36/45] genirq/manage: Rework can_request_irq()

Thomas Gleixner
2025-04-29T06:55:43Z

Use the new guards to get and lock the interrupt descriptor and tidy up the
code.

Make the return value boolean to reflect it's meaning.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
include/linux/irq.h | 2 +-
kernel/irq/manage.c | 21 ++++++++-------------
2 files changed, 9 insertions(+), 14 deletions(-)

--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -700,7 +700,7 @@ extern void note_interrupt(struct irq_de
extern int noirqdebug_setup(char *str);

/* Checks whether the interrupt can be requested by request_irq(): */
-extern int can_request_irq(unsigned int irq, unsigned long irqflags);
+extern bool can_request_irq(unsigned int irq, unsigned long irqflags);

/* Dummy irq-chip implementations: */
extern struct irq_chip no_irq_chip;
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -887,22 +887,17 @@ EXPORT_SYMBOL(irq_set_irq_wake);
* particular irq has been exclusively allocated or is available
* for driver use.
*/
-int can_request_irq(unsigned int irq, unsigned long irqflags)
+bool can_request_irq(unsigned int irq, unsigned long irqflags)
{
- unsigned long flags;
- struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
- int canrequest = 0;
+ scoped_irqdesc_get_and_lock(irq, IRQ_GET_DESC_CHECK_GLOBAL) {
+ struct irq_desc *desc = scoped_irqdesc;

- if (!desc)
- return 0;
-
- if (irq_settings_can_request(desc)) {
- if (!desc->action ||
- irqflags & desc->action->flags & IRQF_SHARED)
- canrequest = 1;
+ if (irq_settings_can_request(desc)) {
+ if (!desc->action || irqflags & desc->action->flags & IRQF_SHARED)
+ return true;
+ }
}
- irq_put_desc_unlock(desc, flags);
- return canrequest;
+ return false;
}

int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)