[PATCH 1/8] dmaengine: Add API to combine configuration and preparation (sg and single)

Bjorn Helgaas helgaas at kernel.org
Wed Dec 10 14:55:44 PST 2025


On Mon, Dec 08, 2025 at 12:09:40PM -0500, Frank Li wrote:
> Previously, configuration and preparation required two separate calls. This
> works well when configuration is done only once during initialization.
> 
> However, in cases where the burst length or source/destination address must
> be adjusted for each transfer, calling two functions is verbose and
> requires additional locking to ensure both steps complete atomically.
> 
> Add a new API and callback device_prep_slave_sg_config that combines
> configuration and preparation into a single operation. If the configuration
> argument is passed as NULL, fall back to the existing implementation.

Add "()" after function name.

> Signed-off-by: Frank Li <Frank.Li at nxp.com>
> ---
>  include/linux/dmaengine.h | 64 +++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 57 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 99efe2b9b4ea9844ca6161208362ef18ef111d96..6c563549133a28e26f1bdc367372b1e4a748afcf 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -835,6 +835,8 @@ struct dma_filter {
>   *	where the address and size of each segment is located in one entry of
>   *	the dma_vec array.
>   * @device_prep_slave_sg: prepares a slave dma operation
> + *	(Depericated, use @device_prep_slave_sg_config)
> + * @device_prep_slave_sg_config: prepares a slave dma operation

s/Depericated/Deprecated/
s/slave dma/slave DMA/ to match other "DMA" uses



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