drm/i915: Ignore fenced commands for gpu access on gen4

Userspace should not have been declaring that it needed fenced GPU
access with gen4+ as those GPUs have no fenced commands, but to be on
the safe side it is easier to ignore userspace in case they did.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 6fc9cc4..1b2ceac 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -432,6 +432,7 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
        struct drm_i915_gem_object *obj;
        struct drm_i915_gem_exec_object2 *entry;
        int ret, retry;
+       bool has_fenced_gpu_access = INTEL_INFO(ring->dev)->gen < 4;
 
        /* Attempt to pin all of the buffers into the GTT.
         * This is done in 3 phases:
@@ -460,6 +461,7 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
                        }
 
                        need_fence =
+                               has_fenced_gpu_access &&
                                entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
                                obj->tiling_mode != I915_TILING_NONE;
                        need_mappable =
@@ -484,6 +486,7 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
                        bool need_fence;
 
                        need_fence =
+                               has_fenced_gpu_access &&
                                entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
                                obj->tiling_mode != I915_TILING_NONE;
 
@@ -498,18 +501,20 @@ i915_gem_execbuffer_reserve(struct intel_ring_buffer *ring,
                                        break;
                        }
 
-                       if (need_fence) {
-                               ret = i915_gem_object_get_fence(obj, ring, 1);
-                               if (ret)
-                                       break;
-                       } else if (entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
-                                  obj->tiling_mode == I915_TILING_NONE) {
-                               /* XXX pipelined! */
-                               ret = i915_gem_object_put_fence(obj);
-                               if (ret)
-                                       break;
+                       if (has_fenced_gpu_access) {
+                               if (need_fence) {
+                                       ret = i915_gem_object_get_fence(obj, ring, 1);
+                                       if (ret)
+                                               break;
+                               } else if (entry->flags & EXEC_OBJECT_NEEDS_FENCE &&
+                                          obj->tiling_mode == I915_TILING_NONE) {
+                                       /* XXX pipelined! */
+                                       ret = i915_gem_object_put_fence(obj);
+                                       if (ret)
+                                               break;
+                               }
+                               obj->pending_fenced_gpu_access = need_fence;
                        }
-                       obj->pending_fenced_gpu_access = need_fence;
 
                        entry->offset = obj->gtt_offset;
                        entry++;