This is a note to let you know that I've just added the patch titled genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: genirq-initialize-request_mutex-if-config_sparse_irq-n.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e8458e7afa855317b14915d7b86ab3caceea7eb6 Mon Sep 17 00:00:00 2001 From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Date: Thu, 4 Apr 2019 15:45:12 +0800 Subject: genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> commit e8458e7afa855317b14915d7b86ab3caceea7eb6 upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/irq/irqdesc.c | 1 + 1 file changed, 1 insertion(+) --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -554,6 +554,7 @@ 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(); Patches currently in stable-queue which might be from wangkefeng.wang@xxxxxxxxxx are queue-4.19/genirq-initialize-request_mutex-if-config_sparse_irq-n.patch