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

Bjorn Helgaas
2025-12-10T22:55:45Z

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@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