[PATCH 0/6] IRQ handling patches backport to 4.14 stable

[Rishabh Bhatnagar <risbhat@amazon.com>]

This patch series backports a bunch of patches related IRQ handling
with respect to freeing the irq line while IRQ is in flight at CPU
or at the hardware level.
Recently we saw this issue in serial 8250 driver where the IRQ was being
freed while the irq was in flight or not yet delivered to the CPU. As a
result the irqchip was going into a wedged state and IRQ was not getting
delivered to the cpu. These patches helped fixed the issue in 4.14
kernel.
Let us know if more patches need backporting.

Lukas Wunner (2):
  genirq: Update code comments wrt recycled thread_mask
  genirq: Synchronize only with single thread on free_irq()

Thomas Gleixner (4):
  genirq: Delay deactivation in free_irq()
  genirq: Fix misleading synchronize_irq() documentation
  genirq: Add optional hardware synchronization for shutdown
  x86/ioapic: Implement irq_get_irqchip_state() callback

 arch/x86/kernel/apic/io_apic.c |  46 ++++++++++++++
 kernel/irq/autoprobe.c         |   6 +-
 kernel/irq/chip.c              |   6 ++
 kernel/irq/cpuhotplug.c        |   2 +-
 kernel/irq/internals.h         |   5 ++
 kernel/irq/manage.c            | 106 ++++++++++++++++++++++-----------
 6 files changed, 133 insertions(+), 38 deletions(-)

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2.37.1