Re: [PATCH 3/3] dmaengine: drop DMA_COMPLETION_NO_ORDER and DMA_OUT_OF_ORDER

[Frank Li]

On Mon, Oct 19, 2026 at 08:06:32AM -0700, Daniel Byrne wrote:
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> DMA_COMPLETION_NO_ORDER (commit 47ec7f09bc10 ("dmaengine: cookie bypass
> for out of order completion")) flagged devices whose completions can
> overtake submission order. On DSA this happens when a work queue (one
> dmaengine channel) belongs to a group that contains several engines.
> Per-channel cookie tracking gives wrong answers in this case, since
> dma_cookie_complete() moves the completed-cookie watermark past
> still-in-flight earlier descriptors, so cookie-order status can report
> DMA_COMPLETE for a running transfer. Clients were told to use
> callbacks only, dmatest refused polled mode, and DMA_OUT_OF_ORDER
> existed as the tx_status answer for such devices.

Thank you for such cleanup. But I have not understood what means. Does
DMA_OUT_OF_ORDER will never happen now?

Frank