[Intel-gfx] [PATCH] drm/i915: Make closing request flush mandatory

[Chris Wilson]

Quoting Joonas Lahtinen (2018-06-13 13:54:01)
> Quoting Chris Wilson (2018-06-12 13:51:35)
> > For symmetry, simplicity and ensuring the request is always truly idle
> > upon its completion, always emit the closing flush prior to emitting the
> > request breadcrumb. Previously, we would only emit the flush if we had
> > started a user batch, but this just leaves all the other paths open to
> > speculation (do they affect the GPU caches or not?) With mm switching, a
> > key requirement is that the GPU is flushed and invalidated before hand,
> > so for absolute safety, we want that closing flush be mandatory.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> No word about perf impact? The patch description matches what it does.
> 
> Assuming we're not murdering any testcases;
> 
> Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

No magpies, thanks for the review.
-Chris