to Phil Kernick:
"The problem is that in full duplex mode, the Conexant chip always reports a
carrier lost error, even when the frame is successfully sent. So, if we
have a Conexant chip, then ignore carrier lost when in full duplex
mode."
Since the Xircom chips seem to have the same issue and since we already
have a workaround for this, just expand the workaround test to also
check for DC_IS_CONEXANT().