[Patch 0/1]drm_irq: Introducing the irq_thread support

[Liu, Chuansheng]

This patch is for introducing the irq thread support in drm_irq.

Why we need irq thread in drm_irq code?
In our GPU system, the gpu interrupt handler need some time even > 1ms to finish,
in that case, the whole system will stay in irq disable status. One case is:
when audio is playing, it sometimes effects the audio quality.

So we have to introduce the irq thread in drm_irq, it can help us move some heavy work into irq thread
and other irq interrupts can be handled in time. Also the IRQF_ONESHOT is helpful for irq thread.

Include one patch:
[PATCH 01/1] drm_irq-Introducing-the-irq_thread-support