Commits
Chris Wilson committed 5dce5b9387a
drm/i915: Wait for completion of pending flips when starved of fences On older generations (gen2, gen3) the GPU requires fences for many operations, such as blits. The display hardware also requires fences for scanouts and this leads to a situation where an arbitrary number of fences may be pinned by old scanouts following a pageflip but before we have executed the unpin workqueue. This is unpredictable by userspace and leads to random EDEADLK when submitting an otherwise benign execbuffer. However, we can detect when we have an outstanding flip and so cause userspace to wait upon their completion before finally declaring that the system is starved of fences. This is really no worse than forcing the GPU to stall waiting for older execbuffer to retire and release their fences before we can reallocate them for the next execbuffer. v2: move the test for a pending fb unpin to a common routine for later reuse during eviction Reported-and-tested-by: dimon@gmx.net Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=73696 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Jon Bloomfield <jon.bloomfield@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>