On Thu, Jul 30, 2020 at 06:45:44PM +0300, Serge Semin wrote: > According to the DW DMA controller Databook (page 40 "3.5 Memory Which version of it? > Peripherals") memory peripherals don't have handshaking interface > connected to the controller, therefore they can never be a flow > controller. Since the CTLx.SRC_MSIZE and CTLx.DEST_MSIZE are > properties valid only for peripherals with a handshaking > interface, we can freely zero these fields out if the memory peripheral > is selected to be the source or the destination of the DMA transfers. > > Note according to the databook, length of burst transfers to memory is > always equal to the number of data items available in a channel FIFO or > data items required to complete the block transfer, whichever is smaller; > length of burst transfers from memory is always equal to the space > available in a channel FIFO or number of data items required to complete > the block transfer, whichever is smaller. But does it really matter if you program there something or not? -- With Best Regards, Andy Shevchenko