diff --git a/arch/mips/sibyte/bcm1480/irq.c b/arch/mips/sibyte/bcm1480/irq.c
index 20af0f1..ba0c4b7 100644
--- a/arch/mips/sibyte/bcm1480/irq.c
+++ b/arch/mips/sibyte/bcm1480/irq.c
@@ -141,11 +141,11 @@
 	unsigned long flags;
 	unsigned int irq_dirty;
 
-	i = first_cpu(mask);
-	if (next_cpu(i, mask) <= NR_CPUS) {
+	if (cpus_weight(mask) != 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
 		return;
 	}
+	i = first_cpu(mask);
 
 	/* Convert logical CPU to physical CPU */
 	cpu = cpu_logical_map(i);