IPW_CONTROL_LINE_DCD
changed_mask = IPW_CONTROL_LINE_DCD;
IPW_CONTROL_LINE_DCD) != 0
if (my & IPW_CONTROL_LINE_DCD)
if ((old_control_lines & IPW_CONTROL_LINE_DCD)
&& !(tty->control_lines & IPW_CONTROL_LINE_DCD)