drm/i915: Only clear the GPU domains upon a successful finish
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.
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@chris-wilson.co.uk> Cc: stable@kernel.org Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>