DMA API and Chunked Transfers

[go2sh]

Hi there,

I'm currently trying to understand how the DMA API works with relation to chunked transfers.

The DMA Engine I'm working on supports chunking DMA transfers for arbitration purposes. E.g 32 Byte transfer with 4 chunks a 8 byte. After the arbitration the channel needs to be requested again by software or hardware. How would those two be represented within the DMA API?
My current implementation uses

• the soure_burst_size to chunk the transfers even though the underlying HW bursts might be different, and
• the dma_start function to re-request a transfer that is in progress.

Especially for the chunking of transfers, it feels like the source_burst_size is not the right field and also this implicit behavior of needing to re-request feels wrong. Any comment on that?

BR,
go2sh