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 <jirisl...@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43427
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: sta...@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(&reg->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(&reg->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

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to