IFORCE_XMIT_RUNNING
!test_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags));
if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
if (!test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags))
clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);