Re: [PATCH RFC 3/3] iio: buffer-dmaengine: Use dma_slave_caps width accessors

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

On Tue, Jun 16, 2026 at 04:40:54PM +0100, Nuno Sá via B4 Relay wrote:
>
> Query the minimum supported source and destination widths through the
> new dma_slave_caps_get_{src,dst}_width_min() helpers rather than
> decoding the raw u32 width mask. This keeps the buffer working with DMA
> controllers that advertise their address widths via the new bitmap
> representation.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> ---

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

>  drivers/iio/buffer/industrialio-buffer-dmaengine.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> index 98acce909854..855e3662cd3d 100644
> --- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> +++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> @@ -229,14 +229,13 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct dma_chan *chan)
>                 return ERR_PTR(-ENOMEM);
>
>         /* Needs to be aligned to the maximum of the minimums */
> -       if (caps.src_addr_widths)
> -               src_width = __ffs(caps.src_addr_widths);
> -       else
> -               src_width = 1;
> -       if (caps.dst_addr_widths)
> -               dest_width = __ffs(caps.dst_addr_widths);
> -       else
> -               dest_width = 1;
> +       src_width = dma_slave_caps_get_src_width_min(&caps);
> +       if (src_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
> +               src_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> +       dest_width = dma_slave_caps_get_dst_width_min(&caps);
> +       if (dest_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
> +               dest_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> +
>         width = max(src_width, dest_width);
>
>         INIT_LIST_HEAD(&dmaengine_buffer->active);
>
> --
> 2.54.0
>
>