Re: [PATCH] [media] videobuf2-dma-contig: allow to vmap contiguous dma buffers

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hello,

On 2014-05-26 16:17, Philipp Zabel wrote:
> This allows drivers to vmap contiguous dma buffers so they can inspect the
> buffer contents with the CPU. This will be needed for the CODA driver's JPEG
> handling. On CODA960, the header parsing has to be done on the CPU. The
> hardware modules can only process the entropy coded segment after all
> registers and tables are set up.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

> ---
>   drivers/media/v4l2-core/videobuf2-dma-contig.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
> index 880be07..6b254b8 100644
> --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
> +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
> @@ -98,6 +98,9 @@ static void *vb2_dc_vaddr(void *buf_priv)
>   {
>   	struct vb2_dc_buf *buf = buf_priv;
>   
> +	if (!buf->vaddr && buf->db_attach)
> +		buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
> +
>   	return buf->vaddr;
>   }
>   
> @@ -735,6 +738,7 @@ static int vb2_dc_map_dmabuf(void *mem_priv)
>   
>   	buf->dma_addr = sg_dma_address(sgt->sgl);
>   	buf->dma_sgt = sgt;
> +	buf->vaddr = NULL;
>   
>   	return 0;
>   }
> @@ -754,6 +758,10 @@ static void vb2_dc_unmap_dmabuf(void *mem_priv)
>   		return;
>   	}
>   
> +	if (buf->vaddr) {
> +		dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr);
> +		buf->vaddr = NULL;
> +	}
>   	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
>   
>   	buf->dma_addr = 0;

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland