Ok, I should read it :)
[from the ARM site]
Scenario (1)
In the case where the DMAC is the flow controller, if I set Burst size (same for both source and destination) to 128 and width is word, then, should I set TransferSize to 512 i.e. 128*4, bytes or 128 (items of burst)?
Answer (1) The TransferSize is the number of transfers to perform when the DMAC is the flow controller. So, in your example, the TransferSize is 128; the total number of bytes transferred will be 128 x 4 = 512