genirq: Make sure the initial affinity is not empty

Srinivas Ramana · KAGA-KOKO · commit bddda606ec76 · 2019-01-15T11:23:27.000+01:00
If all CPUs in the irq_default_affinity mask are offline when an interrupt is initialized then irq_setup_affinity() can set an empty affinity mask for a newly allocated interrupt. Fix this by falling back to cpu_online_mask in case the resulting affinity mask is zero. Signed-off-by: Srinivas Ramana <sramana@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-msm@vger.kernel.org Link: https://lkml.kernel.org/r/1545312957-8504-1-git-send-email-sramana@codeaurora.org
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
@@ -393,6 +393,9 @@ int irq_setup_affinity(struct irq_desc *desc)
 	}
 
 	cpumask_and(&mask, cpu_online_mask, set);
+	if (cpumask_empty(&mask))
+		cpumask_copy(&mask, cpu_online_mask);
+
 	if (node != NUMA_NO_NODE) {
 		const struct cpumask *nodemask = cpumask_of_node(node);
 

Original file line number	Diff line number	Diff line change
`@@ -393,6 +393,9 @@ int irq_setup_affinity(struct irq_desc *desc)`
`393`	`393`	`}`
`394`	`394`
`395`	`395`	`cpumask_and(&mask, cpu_online_mask, set);`
	`396`	`+ if (cpumask_empty(&mask))`
	`397`	`+ cpumask_copy(&mask, cpu_online_mask);`
	`398`	`+`
`396`	`399`	`if (node != NUMA_NO_NODE) {`
`397`	`400`	`const struct cpumask *nodemask = cpumask_of_node(node);`
`398`	`401`