Comment 2 for bug 916368

StacktraceTop:
 prepare_depthbuffer (brw=0x7f8540215010) at brw_misc_state.c:208
 brw_validate_state (brw=0x7f8540215010) at brw_state_upload.c:480
 brw_try_draw_prims (max_index=<optimized out>, min_index=<optimized out>, ib=0x0, nr_prims=1, prim=0x7ffff3cc4110, arrays=0x22bec08, ctx=0x7f8540215010) at brw_draw.c:340
 brw_draw_prims (ctx=0x7f8540215010, arrays=0x22bec08, prim=0x7ffff3cc4110, nr_prims=1, ib=0x0, index_bounds_valid=<optimized out>, min_index=0, max_index=15) at brw_draw.c:431
 vbo_draw_arrays (ctx=0x7f8540215010, mode=7, start=0, count=<optimized out>, numInstances=1) at vbo/vbo_exec_array.c:640