drm/i915: Flush untouched framebuffers before display on !llc
authorChris Wilson <chris@chris-wilson.co.uk>
Mon, 9 Jan 2017 11:19:32 +0000 (11:19 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Wed, 1 Feb 2017 10:54:17 +0000 (10:54 +0000)
commit69aeafeae9b30d797c439a30d1a4ccc8dc5b0eb0
tree841e6ed55b3f78b991f20af5edb660b4dd6bafd7
parente2b06d71bd3f50ac7098b3f2492ea95470b713db
drm/i915: Flush untouched framebuffers before display on !llc

On a non-llc system, the objects are created with .cache_level =
CACHE_NONE and so the transition to uncached for scanout is a no-op.
However, if the object was never written to, it will still be in the CPU
domain (having been zeroed out by shmemfs). Those cachelines need to be
flushed prior to display.

Reported-and-tested-by: Vito Caputo
Fixes: a6a7cc4b7db6 ("drm/i915: Always flush the dirty CPU cache when pinning the scanout")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.10-rc1+
Link: http://patchwork.freedesktop.org/patch/msgid/20170109111932.6342-1-chris@chris-wilson.co.uk
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_gem.c