From: Chris Wilson <chris at chris-wilson.co.uk> By clearing the GPU read domains before waiting upon the buffer, we run the risk of the wait being interrupted and the domains prematurely cleared. The next time we attempt to wait upon the buffer (after userspace handles the signal), we believe that the buffer is idle and so skip the wait. There are a number of bugs across all generations which show signs of an overly haste reuse of active buffers. Such as: https://bugs.freedesktop.org/show_bug.cgi?id=29046 https://bugs.freedesktop.org/show_bug.cgi?id=35863 https://bugs.freedesktop.org/show_bug.cgi?id=38952 https://bugs.freedesktop.org/show_bug.cgi?id=40282 https://bugs.freedesktop.org/show_bug.cgi?id=41098 https://bugs.freedesktop.org/show_bug.cgi?id=41102 https://bugs.freedesktop.org/show_bug.cgi?id=41284 https://bugs.freedesktop.org/show_bug.cgi?id=42141 A couple of those pre-date i915_gem_object_finish_gpu(), so may be unrelated (such as a wild write from a userspace command buffer), but this does look like a convincing cause for most of those bugs. Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> Cc: stable at kernel.org Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch> Reviewed-by: Eugeni Dodonov <eugeni.dodonov at intel.com> --- drivers/gpu/drm/i915/i915_gem.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d560175..036bc58 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3087,10 +3087,13 @@ i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj) return ret; } + ret = i915_gem_object_wait_rendering(obj); + if (ret) + return ret; + /* Ensure that we invalidate the GPU's caches and TLBs. */ obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS; - - return i915_gem_object_wait_rendering(obj); + return 0; } /** -- 1.7.7.3
