On Arduino Due, I set-up DMA transfers using direct control of memory mapped hardware registers.
There is a 16-bit BTSIZE field in CTRLA which indicates the number of (width sized) transfers. If I specify larger than 8191, the value of btcount is trimmed to 13 bits after the DMA channel is enabled. I set chunk size src/dest to 1.
What reference is canonical and correct for the DMAC (dma controller)?
As noted in the links in the comments, multi-buffer transfer can work around this, but since I don't know why it works or fails, it's hard to decide if that solution will work in all cases.