2017-07-01 12:18:36

by Arvind Yadav

Subject: [PATCH] media: vb2 dma-sg: Constify dma_buf_ops structures.

dma_buf_ops are not supposed to change at runtime. All functions
working with dma_buf_ops provided by <linux/dma-buf.h> work with
const dma_buf_ops. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
5238 112 4 5354 14ea drivers/media/v4l2-core/videobuf2-dma-sg.o

File size After adding 'const':
text data bss dec hex filename
5358 0 4 5362 14f2 drivers/media/v4l2-core/videobuf2-dma-sg.o

Signed-off-by: Arvind Yadav <[email protected]>
---
drivers/media/v4l2-core/videobuf2-dma-sg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 8e8798a..f8b4643 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -500,7 +500,7 @@ static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
return vb2_dma_sg_mmap(dbuf->priv, vma);
}

-static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
+static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
.attach = vb2_dma_sg_dmabuf_ops_attach,
.detach = vb2_dma_sg_dmabuf_ops_detach,
.map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
--
2.7.4

2017-07-04 05:23:42

by Marek Szyprowski

Subject: Re: [PATCH] media: vb2 dma-sg: Constify dma_buf_ops structures.

Hi Arvind,

On 2017-07-01 14:18, Arvind Yadav wrote:
> dma_buf_ops are not supposed to change at runtime. All functions
> working with dma_buf_ops provided by <linux/dma-buf.h> work with
> const dma_buf_ops. So mark the non-const structs as const.
>
> File size before:
> text data bss dec hex filename
> 5238 112 4 5354 14ea drivers/media/v4l2-core/videobuf2-dma-sg.o
>
> File size After adding 'const':
> text data bss dec hex filename
> 5358 0 4 5362 14f2 drivers/media/v4l2-core/videobuf2-dma-sg.o
>
> Signed-off-by: Arvind Yadav <[email protected]>

Acked-by: Marek Szyprowski <[email protected]>

> ---
> drivers/media/v4l2-core/videobuf2-dma-sg.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
> index 8e8798a..f8b4643 100644
> --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
> +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
> @@ -500,7 +500,7 @@ static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
> return vb2_dma_sg_mmap(dbuf->priv, vma);
> }
>
> -static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
> +static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
> .attach = vb2_dma_sg_dmabuf_ops_attach,
> .detach = vb2_dma_sg_dmabuf_ops_detach,
> .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,

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