Commit 69aeafea authored Jan 09, 2017 by Chris Wilson

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: a6a7cc4b ("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>

parent e2b06d71

drivers/gpu/drm/i915/i915_gem.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3519,7 +3519,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
		vma->display_alignment = max_t(u64, vma->display_alignment, alignment);

		/* Treat this as an end-of-frame, like intel_user_framebuffer_dirty() */
		if (obj->cache_dirty) {
		if (obj->cache_dirty \|\| obj->base.write_domain == I915_GEM_DOMAIN_CPU) {
		i915_gem_clflush_object(obj, true);
		intel_fb_obj_flush(obj, false, ORIGIN_DIRTYFB);
		}