Re: [PATCH 2/9] dmaengine: dma-axi-dmac: Use bus width capability helpers

On Thu, Jul 30, 2026 at 03:23:09PM +0100, Nuno Sá via B4 Relay wrote:
> [You don't often get email from [email protected]. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> From: Nuno Sá <[email protected]>
>
> Advertise the source and destination bus widths through the new
> dma_set_{src,dst}_bus_width() helpers instead of open-coding the legacy
> BIT() mask. This moves the driver onto the representation that can
> express widths of 32 bytes and above while keeping the legacy u32 fields
> populated during the transition.
>
> While at it, give the channel width members their proper
> enum dma_slave_buswidth type.
>
> Signed-off-by: Nuno Sá <[email protected]>
> ---

Reviewed-by: Frank Li <[email protected]>

>  drivers/dma/dma-axi-dmac.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
> index d47ff27e1408..26912330e3c8 100644
> --- a/drivers/dma/dma-axi-dmac.c
> +++ b/drivers/dma/dma-axi-dmac.c
> @@ -152,8 +152,8 @@ struct axi_dmac_chan {
>         struct list_head active_descs;
>         enum dma_transfer_direction direction;
>
> -       unsigned int src_width;
> -       unsigned int dest_width;
> +       enum dma_slave_buswidth src_width;
> +       enum dma_slave_buswidth dest_width;
>         unsigned int src_type;
>         unsigned int dest_type;
>
> @@ -1262,8 +1262,13 @@ static int axi_dmac_probe(struct platform_device *pdev)
>         dma_dev->device_terminate_all = axi_dmac_terminate_all;
>         dma_dev->device_synchronize = axi_dmac_synchronize;
>         dma_dev->dev = &pdev->dev;
> -       dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
> -       dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width);
> +       ret = dma_set_src_bus_width(dma_dev, dmac->chan.src_width);
> +       if (ret)
> +               return ret;
> +
> +       ret = dma_set_dst_bus_width(dma_dev, dmac->chan.dest_width);
> +       if (ret)
> +               return ret;
>         dma_dev->directions = BIT(dmac->chan.direction);
>         dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
>         dma_dev->max_sg_burst = 31; /* 31 SGs maximum in one burst */
>
> --
> 2.55.0
>
>