Comment 2 for bug 932481

StacktraceTop:
 brw_update_renderbuffer_surface (brw=0x7fce4584e030, rb=0x7fce44a318c0, unit=0) at brw_wm_surface_state.c:905
 brw_update_renderbuffer_surfaces (brw=0x7fce4584e030) at brw_wm_surface_state.c:1002
 brw_upload_state (brw=0x7fce4584e030) at brw_state_upload.c:504
 brw_try_draw_prims (max_index=<optimized out>, min_index=<optimized out>, ib=0x7fff026395a0, nr_prims=1, prim=0x7fff026395c0, arrays=0x7fce457655a8, ctx=0x7fce4584e030) at brw_draw.c:521
 brw_draw_prims (ctx=0x7fce4584e030, arrays=0x7fce457655a8, prim=0x7fff026395c0, nr_prims=1, ib=0x7fff026395a0, index_bounds_valid=<optimized out>, min_index=4294967295, max_index=4294967295, tfb_vertcount=0x0) at brw_draw.c:605