From f21cfb258df6dd3ea0b3e56d75c7e994edb81b35 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Thu, 12 Mar 2009 21:05:42 +0900 Subject: [PATCH] irq: add remove_irq() for freeing of setup_irq() irqs Impact: add new API This patch adds a remove_irq() function for releasing interrupts requested with setup_irq(). Without this patch we have no way of releasing such interrupts since free_irq() today tries to kfree() the irqaction passed with setup_irq(). Signed-off-by: Magnus Damm LKML-Reference: <20090312120542.2926.56609.sendpatchset@rx1.opensource.se> Signed-off-by: Ingo Molnar --- include/linux/irq.h | 1 + kernel/irq/manage.c | 39 ++++++++++++++++++++++++++------------- 2 files changed, 27 insertions(+), 13 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index f899b502f18..56f9988362e 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -236,6 +236,7 @@ typedef struct irq_desc irq_desc_t; #include extern int setup_irq(unsigned int irq, struct irqaction *new); +extern struct irqaction *remove_irq(unsigned int irq, void *dev_id); #ifdef CONFIG_GENERIC_HARDIRQS diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 52ee1713509..8b069a7046e 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -551,20 +551,14 @@ int setup_irq(unsigned int irq, struct irqaction *act) } /** - * free_irq - free an interrupt + * remove_irq - free an interrupt * @irq: Interrupt line to free * @dev_id: Device identity to free * - * Remove an interrupt handler. The handler is removed and if the - * interrupt line is no longer in use by any driver it is disabled. - * On a shared IRQ the caller must ensure the interrupt is disabled - * on the card it drives before calling this function. The function - * does not return until any executing interrupts for this IRQ - * have completed. - * - * This function must not be called from interrupt context. + * Used to remove interrupts statically setup by the early boot process. */ -void free_irq(unsigned int irq, void *dev_id) + +struct irqaction *remove_irq(unsigned int irq, void *dev_id) { struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action, **action_ptr; @@ -573,7 +567,7 @@ void free_irq(unsigned int irq, void *dev_id) WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); if (!desc) - return; + return NULL; spin_lock_irqsave(&desc->lock, flags); @@ -589,7 +583,7 @@ void free_irq(unsigned int irq, void *dev_id) WARN(1, "Trying to free already-free IRQ %d\n", irq); spin_unlock_irqrestore(&desc->lock, flags); - return; + return NULL; } if (action->dev_id == dev_id) @@ -636,7 +630,26 @@ void free_irq(unsigned int irq, void *dev_id) local_irq_restore(flags); } #endif - kfree(action); + return action; +} + +/** + * free_irq - free an interrupt allocated with request_irq + * @irq: Interrupt line to free + * @dev_id: Device identity to free + * + * Remove an interrupt handler. The handler is removed and if the + * interrupt line is no longer in use by any driver it is disabled. + * On a shared IRQ the caller must ensure the interrupt is disabled + * on the card it drives before calling this function. The function + * does not return until any executing interrupts for this IRQ + * have completed. + * + * This function must not be called from interrupt context. + */ +void free_irq(unsigned int irq, void *dev_id) +{ + kfree(remove_irq(irq, dev_id)); } EXPORT_SYMBOL(free_irq); -- 2.41.1