[Intel-gfx] [PATCH] drm/i915: Skip repeated calls to i915_gem_set_wedged()

[Chris Wilson]

Quoting Chris Wilson (2018-08-15 10:25:37)
> If we already wedged, i915_gem_set_wedged() becomes a complicated no-op.
> 
> v2: Make sure the double set-wedged is synchronous, a parallel call
> should not return before the driver is indeed wedged.
> 
> References: https://bugs.freedesktop.org/show_bug.cgi?id=107343
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>

Fwiw, I actually a landed a different version of this patch earlier.

The only advantage (esp. v3) is that we serialise the wedging more
carefully.
-Chris