A_SG_CONTROL
ctrl = t3_read_reg(adapter, A_SG_CONTROL);
t3_set_reg_field(sc, A_SG_CONTROL, F_GLOBALENABLE, F_GLOBALENABLE);
t3_set_reg_field(sc, A_SG_CONTROL, F_GLOBALENABLE, 0);
t3_write_reg(adap, A_SG_CONTROL, ctrl);