From 769ce4643b775496166d09c227b070cc38f9e205 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 13 Feb 2013 21:56:05 +0200 Subject: [PATCH] drm/i915: don't clflush gem objects in stolen memory As explained by Chris Wilson gem objects in stolen memory are always coherent with the GPU so we don't need to ever flush the CPU caches for these. This fixes a breakage - at least with the compact sg patches applied - during the resume/restore gtt mappings path, when we tried to clflush an FB object in stolen memory, but since stolen objects don't have backing pages we passed an invalid page pointer to drm_clflush_page(). Signed-off-by: Imre Deak Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d8618f3..a367801 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3021,6 +3021,13 @@ i915_gem_clflush_object(struct drm_i915_gem_object *obj) if (obj->pages == NULL) return; + /* + * Stolen memory is always coherent with the GPU as it is explicitly + * marked as wc by the system, or the system is cache-coherent. + */ + if (obj->stolen) + return; + /* If the GPU is snooping the contents of the CPU cache, * we do not need to manually clear the CPU cache lines. However, * the caches are only snooped when the render cache is -- 2.7.4