Answering my own question as it was a little bit easier to test than I thought.... no you can't!
Basically it looks like a DMA channel has to do at least 1 transfer, before it will then chain-to ... so a 0 transfer-count effectively is an unusable channel.
So you can either stick with the standard approach and transfer a new transfer_count into the other channel, or you can just copy a single word from A to B and then use chain-to ... both work, but both do an irrelevant transfer (in this case at least.)
The whole "can't chain to itself" thing feels like a missed opportunity ... four bits for the "chain to" field and only 12 channels, there were definitely options Image may be NSFW.
Clik here to view.
Basically it looks like a DMA channel has to do at least 1 transfer, before it will then chain-to ... so a 0 transfer-count effectively is an unusable channel.
So you can either stick with the standard approach and transfer a new transfer_count into the other channel, or you can just copy a single word from A to B and then use chain-to ... both work, but both do an irrelevant transfer (in this case at least.)
The whole "can't chain to itself" thing feels like a missed opportunity ... four bits for the "chain to" field and only 12 channels, there were definitely options Image may be NSFW.
Clik here to view.
Statistics: Posted by essele — Thu Mar 21, 2024 6:10 pm
