From 5a19a59b738add4603b74d1ac5a067b8e6fef59b Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu, 21 Jul 2011 15:14:21 +0100
Subject: [PATCH] --- yaml --- r: 258203 b: refs/heads/master c:
 78359cb86b8c4c8946f6732eac2757fa5e1d4de4 h: refs/heads/master i:   258201:
 d4eee4b304ddbf59fdb9eab44c736403d83538d9   258199:
 e0550d3ec5f14a9f46af833cacd868936184045d v: v3

---
 [refs]                      |  2 +-
 trunk/arch/arm/kernel/irq.c | 39 ++++++++++++++++++++++++++-----------
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/[refs] b/[refs]
index 08f7526f975d..c64e9cc14000 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ca15af19ac07908c8ca386f6d944a18aa343b868
+refs/heads/master: 78359cb86b8c4c8946f6732eac2757fa5e1d4de4
diff --git a/trunk/arch/arm/kernel/irq.c b/trunk/arch/arm/kernel/irq.c
index ab63c05290e5..0f928a131af8 100644
--- a/trunk/arch/arm/kernel/irq.c
+++ b/trunk/arch/arm/kernel/irq.c
@@ -131,46 +131,63 @@ int __init arch_probe_nr_irqs(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static bool migrate_one_irq(struct irq_data *d)
+static bool migrate_one_irq(struct irq_desc *desc)
 {
+	struct irq_data *d = irq_desc_get_irq_data(desc);
 	const struct cpumask *affinity = d->affinity;
+	struct irq_chip *c;
 	bool ret = false;
 
+	/*
+	 * If this is a per-CPU interrupt, or the affinity does not
+	 * include this CPU, then we have nothing to do.
+	 */
+	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
+		return false;
+
 	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-		affinity cpu_online_mask;
+		affinity = cpu_online_mask;
 		ret = true;
 	}
 
-	d->chip->irq_set_affinity(d, affinity, true);
+	c = irq_data_get_irq_chip(d);
+	if (c->irq_set_affinity)
+		c->irq_set_affinity(d, affinity, true);
+	else
+		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
 
 	return ret;
 }
 
 /*
- * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
- * the affinity settings do not allow other CPUs, force them onto any
+ * The current CPU has been marked offline.  Migrate IRQs off this CPU.
+ * If the affinity settings do not allow other CPUs, force them onto any
  * available CPU.
+ *
+ * Note: we must iterate over all IRQs, whether they have an attached
+ * action structure or not, as we need to get chained interrupts too.
  */
 void migrate_irqs(void)
 {
-	unsigned int i, cpu = smp_processor_id();
+	unsigned int i;
 	struct irq_desc *desc;
 	unsigned long flags;
 
 	local_irq_save(flags);
 
 	for_each_irq_desc(i, desc) {
-		struct irq_data *d = &desc->irq_data;
 		bool affinity_broken = false;
 
+		if (!desc)
+			continue;
+
 		raw_spin_lock(&desc->lock);
-		if (desc->action != NULL &&
-		    cpumask_test_cpu(smp_processor_id(), d->affinity))
-			affinity_broken = migrate_one_irq(d);
+		affinity_broken = migrate_one_irq(desc);
 		raw_spin_unlock(&desc->lock);
 
 		if (affinity_broken && printk_ratelimit())
-			pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu);
+			pr_warning("IRQ%u no longer affine to CPU%u\n", i,
+				smp_processor_id());
 	}
 
 	local_irq_restore(flags);