if (tex width < 4), mipmap calculation will be out of range

diff --git a/src/mesa/drivers/dri/i965/brw_tex_layout.c b/src/mesa/drivers/dri/i965/brw_tex_layout.c
index 1353325afff7c5ce3050419f64abf3d197172002..bf7047f644eb803712dae8829d2b04e80db0e2ae 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_tex_layout.c
+++ b/src/mesa/drivers/dri/i965/brw_tex_layout.c
@@ -138,7 +138,7 @@ GLboolean brw_miptree_layout( struct intel_mipmap_tree *mt )
         
         /* Layout_below: step right after second mipmap.
          */
-        if (level == mt->first_level + 1) {
+        if (level == mt->first_level + 1 && mt->pitch > 4) {
            x += mt->pitch / 2;
            x = (x + 3) & ~ 3;
         }