[Intel-gfx] [PATCH] drm/i915: Remove Braswell GGTT update w/a

[Joonas Lahtinen]

On ma, 2017-02-20 at 12:47 +0000, Chris Wilson wrote:
> Testing with concurrent GGTT accesses no longer show the coherency
> problems from yonder, commit 5bab6f60cb4d ("drm/i915: Serialise updates
> to GGTT with access through GGTT on Braswell"). My presumption is that
> the root cause was more likely fixed by commit 3b5724d702ef ("drm/i915:
> Wait for writes through the GTT to land before reading back"), along
> with the use of WC updates to the global gTT in commit 8448661d65f6
> ("drm/i915: Convert clflushed pagetables over to WC maps". Given
> that the original symptoms can no longer be reproduced, time to remove
> the workaround.
> 
> Testcase: igt/gem_concurrenct_blit
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>

Makes one think if the original fix has been appropriate, when adding
stop_machine for a software bug :P

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation