[Intel-gfx] [RFC][PATCH 0/2] drm/i915: Refactor plane enabling/disabling during modeset

[ville.syrjala at linux.intel.com]

I wrote this a while back while investigating the HSW hangs. Just polished
it up a bit, and compile tested. Didn't even boot on real hardware, hence
the RFC for now.

I think this is the right approach to take to make the modeset sequence
clearer. And eventually we want to make everything in
intel_crtc_enable_planes() fully asynchronous anyway.