taglinefilesource code
send_break2155drivers/char/cyclades.csend_break(info, HZ/4); /* 1/4 second */
send_break2162drivers/char/cyclades.csend_break(info, arg ? arg*(HZ/10) : HZ/4);
send_break1841drivers/char/serial.csend_break(info, HZ/4);  /* 1/4 second */
send_break1848drivers/char/serial.csend_break(info, arg ? arg*(HZ/10) : HZ/4);