Re: [PATCH v2 02/18] media: xilinx: Refactor struct xvip_dma

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Ricardo,

Thank you for the patch.

On Tue, May 07, 2024 at 04:27:07PM +0000, Ricardo Ribalda wrote:
> Replace a single element array with a single field.
> 
> The following cocci warning is fixed:
> drivers/media/platform/xilinx/xilinx-dma.h:100:19-22: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)

This is a false positive, as I really meant ab array with a single
element, this isn't a VLA. I think the current code is a bit clearer,
but I don't think this patch is such a regression in terms of
readability that I'll argue for the driver to remain the last coccinelle
warning :-)

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/platform/xilinx/xilinx-dma.c | 4 ++--
>  drivers/media/platform/xilinx/xilinx-dma.h | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> index a96de5d388a1..a1687b868a44 100644
> --- a/drivers/media/platform/xilinx/xilinx-dma.c
> +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> @@ -348,8 +348,8 @@ static void xvip_dma_buffer_queue(struct vb2_buffer *vb)
>  	}
>  
>  	dma->xt.frame_size = 1;
> -	dma->sgl[0].size = dma->format.width * dma->fmtinfo->bpp;
> -	dma->sgl[0].icg = dma->format.bytesperline - dma->sgl[0].size;
> +	dma->sgl.size = dma->format.width * dma->fmtinfo->bpp;
> +	dma->sgl.icg = dma->format.bytesperline - dma->sgl.size;
>  	dma->xt.numf = dma->format.height;
>  
>  	desc = dmaengine_prep_interleaved_dma(dma->dma, &dma->xt, flags);
> diff --git a/drivers/media/platform/xilinx/xilinx-dma.h b/drivers/media/platform/xilinx/xilinx-dma.h
> index 9c6d4c18d1a9..18f77e1a7b39 100644
> --- a/drivers/media/platform/xilinx/xilinx-dma.h
> +++ b/drivers/media/platform/xilinx/xilinx-dma.h
> @@ -97,7 +97,7 @@ struct xvip_dma {
>  	struct dma_chan *dma;
>  	unsigned int align;
>  	struct dma_interleaved_template xt;
> -	struct data_chunk sgl[1];
> +	struct data_chunk sgl;
>  };
>  
>  #define to_xvip_dma(vdev)	container_of(vdev, struct xvip_dma, video)

-- 
Regards,

Laurent Pinchart