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-rw-r--r--kernel/irq/handle.c52
1 files changed, 49 insertions, 3 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 343acec..26e0875 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -339,6 +339,15 @@ 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);
+}
+
DEFINE_TRACE(irq_handler_entry);
DEFINE_TRACE(irq_handler_exit);
@@ -354,8 +363,6 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
- WARN_ONCE(!in_irq(), "BUG: IRQ handler called from non-hardirq context!");
-
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
@@ -363,8 +370,47 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
trace_irq_handler_entry(irq, action);
ret = action->handler(irq, action->dev_id);
trace_irq_handler_exit(irq, action, ret);
- if (ret == IRQ_HANDLED)
+
+ 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
+ * interrupt. The hardirq handler above has
+ * disabled the device interrupt, so no irq
+ * storm is lurking.
+ */
+ if (likely(!test_bit(IRQTF_DIED,
+ &action->thread_flags))) {
+ set_bit(IRQTF_RUNTHREAD, &action->thread_flags);
+ wake_up_process(action->thread);
+ }
+
+ /* Fall through to add to randomness */
+ case IRQ_HANDLED:
status |= action->flags;
+ break;
+
+ default:
+ break;
+ }
+
retval |= ret;
action = action->next;
} while (action);
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