Honored Contributor
Honored Contributor#1 Either the thing emptying the DCFIFO can't keep up or the DCFIFO is too shallow. Yes the SGDMA will stall if the DCFIFO is full since the FIFO will dessert the ST ready signal which will then stop the SGDMA from reading until there is more room available.
# 2 There are different ways. To have predictable memory usage you can carve up a block of memory into descriptors and divide them amungst the SGDMAs. That method allows you to build circular buffers easily as well as makes it much easier to transverse the linked-list (if you know where they are in memory then you don't have to jump through the list). # 3 Nope the descriptor still remains in memory. When the transfer completes the SGDMA will write the actual_bytes transfer into the descriptor field as well as set "owned by hardware" to 0. So if you want to reuse those descriptors you might be able to just flip the owned by hardware back to 1.
