[PATCH] genirq: Fix uninitialized request_mutex

[Kefeng Wang]

When !CONFIG_SPARSE_IRQ, request_mutex of struct irq_desc won't
be initialiezed, it leads to system hung, fix it.

Fixes: 9114014cf4e6 ("genirq: Add mutex to irq desc to serialize request/free_irq()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
 kernel/irq/irqdesc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 13539e12cd80..9f8a709337cf 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -558,6 +558,7 @@ int __init early_irq_init(void)
 		alloc_masks(&desc[i], node);
 		raw_spin_lock_init(&desc[i].lock);
 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
+		mutex_init(&desc[i].request_mutex);
 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
 	}
 	return arch_early_irq_init();
-- 
2.20.1