taglinefilesource code
xmit_tail418drivers/char/serial.cserial_out(info, UART_TX, info->xmit_buf[info->xmit_tail++]);
xmit_tail419drivers/char/serial.cinfo->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
xmit_tail954drivers/char/serial.cinfo->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
xmit_tail1293drivers/char/serial.cinfo->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
xmit_tail110include/linux/serial.hint      xmit_tail;