Lines Matching refs:tail
430 if (xmit->tail < xmit->head || xmit->head == 0) {
432 sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
436 sg_set_buf(sgl, xmit->buf + xmit->tail,
437 UART_XMIT_SIZE - xmit->tail);
483 xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
706 writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
707 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
739 lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
740 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1036 if (ring->head < ring->tail) {
1037 count = sport->rx_sgl.length - ring->tail;
1039 ring->buf + ring->tail, count);
1040 ring->tail = 0;
1043 if (ring->head > ring->tail) {
1044 count = ring->head - ring->tail;
1046 ring->buf + ring->tail, count);
1047 ring->tail = ring->head;
1130 * ring->tail points to the beginning of data to be read by the
1151 * However ring->tail must always points inside the dma buffer:
1152 * 0 <= ring->tail <= sport->rx_sgl.length - 1
1155 * where head is lower than tail. In such a case, we first read from
1156 * tail to the end of the buffer then reset tail.
1158 if (ring->head < ring->tail) {
1159 count = sport->rx_sgl.length - ring->tail;
1161 tty_insert_flip_string(port, ring->buf + ring->tail, count);
1162 ring->tail = 0;
1166 /* Finally we read data from tail to head */
1167 if (ring->tail < ring->head) {
1168 count = ring->head - ring->tail;
1169 tty_insert_flip_string(port, ring->buf + ring->tail, count);
1173 ring->tail = ring->head;
1290 sport->rx_ring.tail = 0;