pub fn is_done(&self) -> bool {
        let State::Active(rx, tx) = &self.0.state else {
            unreachable!()
        };

        // Wait for transmission to finish, and wait for the RX channel to receive the
        // one and only EOF that DmaTxBuf will send.
        tx.is_done()
            && rx
                .m2m
                .channel
                .pending_in_interrupts()
                .contains(DmaRxInterrupt::SuccessfulEof)
    }
Returns true when [Self::wait] will not block.
esp-hal/src/dma/m2m.rs