msg_xfer
*rsp = msg_xfer(qdev, wrappers, qdev->next_seq_num - 1, false);
rsp = msg_xfer(qdev, wrappers, qdev->next_seq_num - 1, true);
spi_message_add_tail(&msg_xfer, &msg);
struct spi_transfer msg_xfer = {
msg_xfer.tx_buf = chip->spi_wbuffer;
msg_xfer.rx_buf = chip->spi_rbuffer;