tree b7332e00d00a4e1f1a13b01b8da7237b644e5eb0
parent e8137f4f5088d763ced1db82d3974336b76e1bd2
author Marc Zyngier <marc.zyngier@arm.com> 1425659863 +0000
committer Jason Cooper <jason@lakedaemon.net> 1425792780 +0000

irqchip: gicv3-its: Fix unsafe locking reported by lockdep

When compiled with CONFIG_LOCKDEP, the kernel shouts badly, saying
that my locking is unsafe. I'm afraid the kernel is right:

       CPU0                    CPU1
       ----                    ----
  lock(&its->lock);
                               local_irq_disable();
                               lock(&irq_desc_lock_class);
                               lock(&its->lock);
  <Interrupt>
    lock(&irq_desc_lock_class);

 *** DEADLOCK ***

The fix is to always take its->lock with interrupts disabled.

Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-5-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>