Re: [PATCH] docs: dmaengine: clarify ordering rules around cookie completion

[Frank Li <Frank.li@oss.nxp.com>]

On Fri, Oct 09, 2026 at 11:37:44AM +0200, Vinod Koul wrote:
> Sashiko pointed in [1] about the cookie completion order. It is good to
> Document that for ensuring that dma buffer is flushed and no stale data
> is seeing by consumer, we need to make sure such action is taken before
> drivers invoke dma cookie completion.
>
> [1]: https://lore.kernel.org/r/20260917072507.5BDB61F000FF@smtp.kernel.org
>
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> ---
>  Documentation/driver-api/dmaengine/provider.rst | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst
> index 2897ade67b39..1bcbce705659 100644
> --- a/Documentation/driver-api/dmaengine/provider.rst
> +++ b/Documentation/driver-api/dmaengine/provider.rst
> @@ -557,6 +557,11 @@ dma_cookie_t
>  - Not really relevant any more since the introduction of ``virt-dma``
>    that abstracts it away.
>
> +- dmaengine drivers need to ensure buffers are flushed before invoking
> +  vchan_cookie_complete() or dma_cookie_complete(). This would imply a call
> +  to unmapping buffers or any such architcure calls to ensure caller seeing

Sashiko report a typo architcure

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> +  buffers are flushed is done before invoking these calls.
> +
>  dma_vec
>
>  - A small structure that contains a DMA address and length.
> --
> 2.53.0
>