irqchip/gic-v3-its: Fix reprogramming of redistributors on CPU hotplug

irqchip/gic-v3-its: Fix reprogramming of redistributors on CPU hotplug

[ Upstream commit 82f499c8811149069ec958b72a86643a7a289b25 ]

Enabling LPIs was made a lot stricter recently, by checking that they are
disabled before enabling them. By doing so, the CPU hotplug case was missed
altogether, which leaves LPIs enabled on hotplug off (expecting the CPU to
eventually come back), and won't write a different value anyway on hotplug
on.

So skip that check if that particular case is detected

Fixes: 6eb486b66a30 ("irqchip/gic-v3: Ensure GICR_CTLR.EnableLPI=0 is observed before enabling")
Reported-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lkml.kernel.org/r/20180622095254.5906-8-marc.zyngier@arm.com
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>