FLEXCAN_IFLAG_RX_FIFO_AVAILABLE
if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, ®s->iflag1);
if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;