[Mesa-dev] [RFC PATCH 10/12] hsw hiz: Remove x/y offset restriction for hiz

[Jordan Justen]

This restriction was related to programming the offset fields
of the depth buffer packet. We are now setting these offsets
to 0 now, so this restriction should no longer be required.

Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/mesa/drivers/dri/i965/intel_mipmap_tree.c |   24 ------------------------
 1 file changed, 24 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index d6988e0..900e1c2 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -1244,31 +1244,7 @@ intel_miptree_slice_enable_hiz(struct brw_context *brw,
    assert(mt->hiz_mt);
 
    if (brw->is_haswell) {
-      /* Disable HiZ for some slices to work around a hardware bug.
-       *
-       * Haswell hardware fails to respect
-       * 3DSTATE_DEPTH_BUFFER.Depth_Coordinate_Offset_X/Y when during HiZ
-       * ambiguate operations.  The failure is inconsistent and affected by
-       * other GPU contexts. Running a heavy GPU workload in a separate
-       * process causes the failure rate to drop to nearly 0.
-       *
-       * To workaround the bug, we enable HiZ only when we can guarantee that
-       * the Depth Coordinate Offset fields will be set to 0. The function
-       * brw_get_depthstencil_tile_masks() is used to calculate the fields,
-       * and the function is sometimes called in such a way that the presence
-       * of an attached stencil buffer changes the fuction's return value.
-       *
-       * The largest tile size considered by brw_get_depthstencil_tile_masks()
-       * is that of the stencil buffer. Therefore, if this hiz slice's
-       * corresponding depth slice has an offset that is aligned to the
-       * stencil buffer tile size, 64x64 pixels, then
-       * 3DSTATE_DEPTH_BUFFER.Depth_Coordinate_Offset_X/Y is set to 0.
-       */
       const struct intel_mipmap_level *l = &mt->level[level];
-      const struct intel_mipmap_slice *s = &l->slice[layer];
-      if ((s->x_offset & 63) || (s->y_offset & 63)) {
-         return false;
-      }
 
       /* Disable HiZ for LOD > 0 unless the width is 8 aligned
        * and the height is 4 aligned. This allows our HiZ support
-- 
1.7.10.4