taglinefilesource code
sbusy549drivers/net/slip.csl->sbusy++;
sbusy870drivers/net/slip.cstats.tx_dropped = sl->sbusy;
sbusy1185drivers/net/slip.csl->sbusy    = 0;      /* "xmit busy" counter  */
sbusy56drivers/net/slip.hunsigned long    sbusy;    /* "transmitter busy" counter  */