Commit-ID: f48fe81e5b032914183e9a17052313720c2cac56
Gitweb: http://git.kernel.org/tip/f48fe81e5b032914183e9a17052313720c2cac56
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 24 Mar 2009 11:46:22 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 24 Mar 2009 12:15:23 +0100
genirq: threaded irq handlers review fixups
Delta patch to address the review comments.
- Implement warning when IRQ_WAKE_THREAD is requested and no
thread handler installed
- coding style fixes
Pointed-out-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/interrupt.h | 2 ++
kernel/irq/handle.c | 29 ++++++++++++++++++++++++-----
kernel/irq/manage.c | 17 +++++++----------
3 files changed, 33 insertions(+), 15 deletions(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index dbf6a6f..266a5f5 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -63,10 +63,12 @@
* Bits used by threaded handlers:
* IRQTF_RUNTHREAD - signals that the interrupt handler thread should run
* IRQTF_DIED - handler thread died
+ * IRQTF_WARNED - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
*/
enum {
IRQTF_RUNTHREAD,
IRQTF_DIED,
+ IRQTF_WARNED,
};
typedef irqreturn_t (*irq_handler_t)(int, void *);
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index fe8f453..38b49a9 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -338,6 +338,15 @@ irqreturn_t no_action(int cpl, void *dev_id)
return IRQ_NONE;
}
+static void warn_no_thread(unsigned int irq, struct irqaction *action)
+{
+ if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags))
+ return;
+
+ printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "
+ "but no thread function available.", irq, action->name);
+}
+
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
@@ -361,6 +370,21 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
switch (ret) {
case IRQ_WAKE_THREAD:
/*
+ * Set result to handled so the spurious check
+ * does not trigger.
+ */
+ ret = IRQ_HANDLED;
+
+ /*
+ * Catch drivers which return WAKE_THREAD but
+ * did not set up a thread function
+ */
+ if (unlikely(!action->thread_fn)) {
+ warn_no_thread(irq, action);
+ break;
+ }
+
+ /*
* Wake up the handler thread for this
* action. In case the thread crashed and was
* killed we just pretend that we handled the
@@ -374,11 +398,6 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
wake_up_process(action->thread);
}
- /*
- * Set it to handled so the spurious check
- * does not trigger.
- */
- ret = IRQ_HANDLED;
/* Fall through to add to randomness */
case IRQ_HANDLED:
status |= action->flags;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index a4c1ab8..a3eb7ba 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -407,20 +407,17 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
return ret;
}
-static inline int irq_thread_should_run(struct irqaction *action)
-{
- return test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags);
-}
-
static int irq_wait_for_interrupt(struct irqaction *action)
{
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
- if (irq_thread_should_run(action)) {
+
+ if (test_and_clear_bit(IRQTF_RUNTHREAD,
+ &action->thread_flags)) {
__set_current_state(TASK_RUNNING);
return 0;
- } else
- schedule();
+ }
+ schedule();
}
return -1;
}
@@ -820,8 +817,8 @@ EXPORT_SYMBOL(free_irq);
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Primary handler for threaded interrupts
- * @thread_fn: Function called from the irq handler thread
- * If NULL, no irq thread is created
+ * @thread_fn: Function called from the irq handler thread
+ * If NULL, no irq thread is created
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
--
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