pub fn is_done(&self) -> bool {
        if self.dma_result.is_some() {
            return true;
        }
        let ch = &self.parl_io.rx_channel;
        ch.is_done() || ch.has_eof_error() || ch.has_dscr_empty_error()
    }
Returns true when [Self::wait] will not block.
esp-hal/src/parl_io.rs