From c4347efb98b2506807259336ac1c4c0a9ded85e6 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@woody.linux-foundation.org>
Date: Thu, 24 May 2007 08:37:14 -0700
Subject: [PATCH] --- yaml --- r: 56927 b: refs/heads/master c:
 92ea77275b5345c1300433f28689493dc4163f24 h: refs/heads/master i:   56925:
 74ce242bd202f379a3abb221d1ea8926f173656d   56923:
 ed3cd0aa828f4d53f1e72c0400b988c021d06b1b   56919:
 6243437f6cd07d72888665333df615387df6cb82   56911:
 f60716bfc2f99a79d43b5323ae503a8bc7be0955   56895:
 2d6c5d62af1c1a57a737f433ce3afa4e676e2f67 v: v3

---
 [refs]                      |  2 +-
 trunk/kernel/irq/spurious.c | 46 +++++++++++++++++++++++++++++--------
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index e5ea6e7d6597..567bccd56f22 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: db2668fdbeb2e3c95ebadf95856c9e31a8a8d569
+refs/heads/master: 92ea77275b5345c1300433f28689493dc4163f24
diff --git a/trunk/kernel/irq/spurious.c b/trunk/kernel/irq/spurious.c
index b0d81aae472f..bd9e272d55e9 100644
--- a/trunk/kernel/irq/spurious.c
+++ b/trunk/kernel/irq/spurious.c
@@ -135,6 +135,39 @@ report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
 	}
 }
 
+static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
+{
+	struct irqaction *action;
+
+	if (!irqfixup)
+		return 0;
+
+	/* We didn't actually handle the IRQ - see if it was misrouted? */
+	if (action_ret == IRQ_NONE)
+		return 1;
+
+	/*
+	 * But for 'irqfixup == 2' we also do it for handled interrupts if
+	 * they are marked as IRQF_IRQPOLL (or for irq zero, which is the
+	 * traditional PC timer interrupt.. Legacy)
+	 */
+	if (irqfixup < 2)
+		return 0;
+
+	if (!irq)
+		return 1;
+
+	/*
+	 * Since we don't get the descriptor lock, "action" can
+	 * change under us.  We don't really care, but we don't
+	 * want to follow a NULL pointer. So tell the compiler to
+	 * just load it once by using a barrier.
+	 */
+	action = desc->action;
+	barrier();
+	return action && (action->flags & IRQF_IRQPOLL);
+}
+
 void note_interrupt(unsigned int irq, struct irq_desc *desc,
 		    irqreturn_t action_ret)
 {
@@ -144,15 +177,10 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
 			report_bad_irq(irq, desc, action_ret);
 	}
 
-	if (unlikely(irqfixup)) {
-		/* Don't punish working computers */
-		if ((irqfixup == 2 && ((irq == 0) ||
-				(desc->action->flags & IRQF_IRQPOLL))) ||
-				action_ret == IRQ_NONE) {
-			int ok = misrouted_irq(irq);
-			if (action_ret == IRQ_NONE)
-				desc->irqs_unhandled -= ok;
-		}
+	if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
+		int ok = misrouted_irq(irq);
+		if (action_ret == IRQ_NONE)
+			desc->irqs_unhandled -= ok;
 	}
 
 	desc->irq_count++;