+ /**
+ * From Graphics BSpec: 3D-Media-GPGPU Engine > 3D Pipeline Stages >
+ * Geometry > Geometry Shader > State:
+ *
+ * "Note: Because of corruption in IVB:GT2, software needs to flush the
+ * whole fixed function pipeline when the GS enable changes value in
+ * the 3DSTATE_GS."
+ *
+ * The hardware architects have clarified that in this context "flush the
+ * whole fixed function pipeline" means to emit a PIPE_CONTROL with the "CS
+ * Stall" bit set.
+ */
+ if (!brw->is_haswell && brw->gt == 2 && brw->gs.enabled)
+ gen7_emit_cs_stall_flush(brw);
+