r600g: fix possible issue with stencil mipmap rendering

Somehow I only hit this issue with my latest libdrm changes.
This won't be needed with DB texturing.

NOTE: This is a candidate for the 9.0 branch.

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index c126e7dfc3d50f52c4b52e7bd0e7a1e9c4e28992..e35314f6c0e0e5a1ff7882a46a603bc9fbeb0788 100644 (file)
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -1496,13 +1496,24 @@ static void evergreen_init_depth_surface(struct r600_context *rctx,
 
        if (rtex->surface.flags & RADEON_SURF_SBUFFER) {
                uint64_t stencil_offset = rtex->surface.stencil_offset;
-               unsigned stile_split = rtex->surface.stencil_tile_split;
+               unsigned i, stile_split = rtex->surface.stencil_tile_split;
 
                stile_split = eg_tile_split(stile_split);
                stencil_offset += r600_resource_va(screen, surf->base.texture);
                stencil_offset += rtex->surface.level[level].offset / 4;
                stencil_offset >>= 8;
 
+               /* We're guessing the stencil offset from the depth offset.
+                * Make sure each mipmap level has a unique offset. */
+               for (i = 1; i <= level; i++) {
+                       /* If two levels have the same address, add 256
+                        * to the offset of the smaller level. */
+                       if ((rtex->surface.level[i-1].offset / 4) >> 8 ==
+                           (rtex->surface.level[i].offset / 4) >> 8) {
+                               stencil_offset++;
+                       }
+               }
+
                surf->db_stencil_base = stencil_offset;
                surf->db_stencil_info = S_028044_FORMAT(V_028044_STENCIL_8) |
                                        S_028044_TILE_SPLIT(stile_split);