pub const fn min_compatible_alignment(self) -> usize {
        let in_alignment = self.min_dram_alignment(TransferDirection::In);
        let out_alignment = self.min_dram_alignment(TransferDirection::Out);
        let alignment = max(in_alignment, out_alignment);

        #[cfg(psram_dma)]
        let alignment = max(alignment, self.external_memory as usize);

        alignment
    }
Calculates an alignment that is compatible with the current burst
configuration.

This is an over-estimation so that Descriptors can be safely used with
any DMA channel in any direction.
esp-hal/src/dma/buffers.rs