The BLT commands on gen2/3 utilize the fence registers and so we cannot modify any fences for the object whilst those commands are in flight. Currently we marked tiled commands as occupying a fence, but forgot to restrict the untiled commands from preventing a fence being assigned before they were completed. One side-effect is that we ten have to double check that a fence was allocated for a fenced buffer during move-to-active. Reported-by: Jiri Slaby <jirislaby at gmail.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43427 Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> Cc: stable at kernel.org --- drivers/gpu/drm/i915/i915_gem.c | 15 +++++++++------ drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 +- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f79bd02..0918f02 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1656,16 +1656,19 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj, list_move_tail(&obj->ring_list, &ring->active_list); obj->last_rendering_seqno = seqno; - if (obj->fenced_gpu_access) { - struct drm_i915_fence_reg *reg; - - BUG_ON(obj->fence_reg == I915_FENCE_REG_NONE); + if (obj->fenced_gpu_access) { obj->last_fenced_seqno = seqno; obj->last_fenced_ring = ring; - reg = &dev_priv->fence_regs[obj->fence_reg]; - list_move_tail(®->lru_list, &dev_priv->mm.fence_list); + /* Bump MRU to take account of the delayed flush */ + if (obj->fence_reg != I915_FENCE_REG_NONE) { + struct drm_i915_fence_reg *reg; + + reg = &dev_priv->fence_regs[obj->fence_reg]; + list_move_tail(®->lru_list, + &dev_priv->mm.fence_list); + } } } diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 21fd5a4..9b33e10 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -498,8 +498,8 @@ pin_and_fence_object(struct drm_i915_gem_object *obj, if (ret) goto err_unpin; } + obj->pending_fenced_gpu_access = true; } - obj->pending_fenced_gpu_access = need_fence; } entry->offset = obj->gtt_offset; -- 1.7.9.1
