538 	struct circ_buf *circ;  in uart_put_char()  local
542 	circ = &state->xmit;  in uart_put_char()
544 	if (!circ->buf) {  in uart_put_char()
549 	if (port && uart_circ_chars_free(circ) != 0) {  in uart_put_char()
550 		circ->buf[circ->head] = c;  in uart_put_char()
551 		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);  in uart_put_char()
568 	struct circ_buf *circ;  in uart_write()  local
582 	circ = &state->xmit;  in uart_write()
583 	if (!circ->buf) {  in uart_write()
589 		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);  in uart_write()
594 		memcpy(circ->buf + circ->head, buf, c);  in uart_write()
595 		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);  in uart_write()