[tip:irq/urgent] genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n

[tip-bot for Kefeng Wang]

Commit-ID:  e8458e7afa855317b14915d7b86ab3caceea7eb6
Gitweb:     https://git.kernel.org/tip/e8458e7afa855317b14915d7b86ab3caceea7eb6
Author:     Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
AuthorDate: Thu, 4 Apr 2019 15:45:12 +0800
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 5 Apr 2019 14:37:56 +0200

genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n

When CONFIG_SPARSE_IRQ is disable, the request_mutex in struct irq_desc
is not initialized which causes malfunction.

Fixes: 9114014cf4e6 ("genirq: Add mutex to irq desc to serialize request/free_irq()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20190404074512.145533-1-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();