We did not implement an irq_cpu_offline callback for our irqchip, yet we
support setting a given IRQ's affinity. This resulted in interrupts
whose affinity mask included CPUs being taken offline not to work
correctly once the CPU had been put offline.

Fixes: 5f7f0317ed28 ("IRQCHIP: Add new driver for BCM7038-style level 1 
interrupt controllers")
Signed-off-by: Florian Fainelli <[email protected]>
---
 drivers/irqchip/irq-bcm7038-l1.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c
index 0fea985ef1dc..529968ac38c0 100644
--- a/drivers/irqchip/irq-bcm7038-l1.c
+++ b/drivers/irqchip/irq-bcm7038-l1.c
@@ -216,6 +216,30 @@ static int bcm7038_l1_set_affinity(struct irq_data *d,
        return 0;
 }
 
+static void bcm7038_l1_cpu_offline(struct irq_data *d)
+{
+       struct cpumask *mask = irq_data_get_affinity_mask(d);
+       int cpu = smp_processor_id();
+       cpumask_t new_affinity;
+
+       /* This CPU was not on the affinity mask */
+       if (!cpumask_test_cpu(cpu, mask))
+               return;
+
+       if (cpumask_weight(mask) > 1) {
+               /* Multiple CPU affinity, remove this CPU from the affinity
+                * mask
+                */
+               cpumask_copy(&new_affinity, mask);
+               cpumask_clear_cpu(cpu, &new_affinity);
+       } else {
+               /* Only CPU, put on the lowest online CPU */
+               cpumask_clear(&new_affinity);
+               cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
+       }
+       irq_set_affinity_locked(d, &new_affinity, false);
+}
+
 static int __init bcm7038_l1_init_one(struct device_node *dn,
                                      unsigned int idx,
                                      struct bcm7038_l1_chip *intc)
@@ -267,6 +291,7 @@ static struct irq_chip bcm7038_l1_irq_chip = {
        .irq_mask               = bcm7038_l1_mask,
        .irq_unmask             = bcm7038_l1_unmask,
        .irq_set_affinity       = bcm7038_l1_set_affinity,
+       .irq_cpu_offline        = bcm7038_l1_cpu_offline,
 };
 
 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
-- 
2.7.4

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