fn set_rx_fifo_full_threshold(&self, threshold: u16) -> Result<(), ConfigError> {
        if threshold > Self::RX_FIFO_MAX_THRHD {
            return Err(ConfigError::UnsupportedRxFifoThreshold);
        }

        self.regs()
            .conf1()
            .modify(|_, w| unsafe { w.rxfifo_full_thrhd().bits(threshold as _) });

        Ok(())
    }
Configures the RX-FIFO threshold

## Errors

[ConfigError::UnsupportedRxFifoThreshold] if the provided value exceeds
[`Info::RX_FIFO_MAX_THRHD`].
esp-hal/src/uart.rs