[Intel-gfx] [PATCH 2/2] drm/i915: Fix timeout handling in i915_gem_shrinker_vmap

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-01-09 14:12:47)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> The code tries to grab struct mutex for 5ms every time the unlocked GPU
> idle wait succeeds. But the GPU idle wait itself is practically unbound
> which means the 5ms timeout might not be honoured.

The arbitrary timeout is merely advisory. If we hang, we get to recover
everything we can!
-Chris