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-rw-r--r--kernel/irq/handle.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 470d08c..bdb1803 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -54,14 +54,18 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
{
/*
- * Wake up the handler thread for this action. In case the
- * thread crashed and was killed we just pretend that we
- * handled the interrupt. The hardirq handler has disabled the
- * device interrupt, so no irq storm is lurking. If the
+ * In case the thread crashed and was killed we just pretend that
+ * we handled the interrupt. The hardirq handler has disabled the
+ * device interrupt, so no irq storm is lurking.
+ */
+ if (action->thread->flags & PF_EXITING)
+ return;
+
+ /*
+ * Wake up the handler thread for this action. If the
* RUNTHREAD bit is already set, nothing to do.
*/
- if (test_bit(IRQTF_DIED, &action->thread_flags) ||
- test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
+ if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
return;
/*
@@ -110,6 +114,18 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
* threads_oneshot untouched and runs the thread another time.
*/
desc->threads_oneshot |= action->thread_mask;
+
+ /*
+ * We increment the threads_active counter in case we wake up
+ * the irq thread. The irq thread decrements the counter when
+ * it returns from the handler or in the exit path and wakes
+ * up waiters which are stuck in synchronize_irq() when the
+ * active count becomes zero. synchronize_irq() is serialized
+ * against this code (hard irq handler) via IRQS_INPROGRESS
+ * like the finalize_oneshot() code. See comment above.
+ */
+ atomic_inc(&desc->threads_active);
+
wake_up_process(action->thread);
}
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