axi dma receive frame length in multi channel mode
Without multi channel mode (i.e. C_ENABLE_MULTI_CHANNEL == 0), there is a very useful feature on the S2MM side where the actual size of the TLAST-bounded frame is saved back into the descriptor's status field. When you enable mutli channel mode, this feature seems to disappear. Where the actual frame size was is replaced by the mildely useful axi-stream channel parameters, i.e. TUSER/TDEST/TID. Is the S2MM actual frame size saved anywhere in multi channel mode? I've checked all of the descriptor fields and the actual size doesn't show up anywhere, so I pretty much know the answer to my question. A corollary question is then, why the heck was this useful feature removed?
I go agree that the feature was useful but the requirement for multi channel mode itself is that the received data has to be specific. It is as though using the DMA with Multi_channel = 0 and Use_rxlength =1. Hence this cant be implemented.