Re: [PATCH 3/3] media: videobuf2: set dma_coherent flag for DMA-buf

[Hans Verkuil <hverkuil@xxxxxxxxx>]

Hi Christian,

On 20/10/2022 14:13, Christian König wrote:
> When a device is snooping the CPU cache we assume that all importers
> must snoop the CPU cache as well.
> 
> Execpt for vmalloc allocations since those implement mmap() imports must
> always snoop the cache or we will run into coherency problems.

Looks reasonable.

For this series:

Acked-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>

Regards,

	Hans

> 
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> ---
>  drivers/media/common/videobuf2/videobuf2-dma-contig.c | 2 ++
>  drivers/media/common/videobuf2/videobuf2-dma-sg.c     | 2 ++
>  drivers/media/common/videobuf2/videobuf2-vmalloc.c    | 1 +
>  3 files changed, 5 insertions(+)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> index 555bd40fa472..57433310c55c 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> @@ -11,6 +11,7 @@
>   */
>  
>  #include <linux/dma-buf.h>
> +#include <linux/dma-map-ops.h>
>  #include <linux/module.h>
>  #include <linux/refcount.h>
>  #include <linux/scatterlist.h>
> @@ -507,6 +508,7 @@ static struct dma_buf *vb2_dc_get_dmabuf(struct vb2_buffer *vb,
>  	exp_info.size = buf->size;
>  	exp_info.flags = flags;
>  	exp_info.priv = buf;
> +	exp_info.coherent = dev_is_dma_coherent(vb->vb2_queue->dev);
>  
>  	if (!buf->sgt_base)
>  		buf->sgt_base = vb2_dc_get_base_sgt(buf);
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> index 36981a5b5c53..dbdd753e4a39 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> @@ -10,6 +10,7 @@
>   * the Free Software Foundation.
>   */
>  
> +#include <linux/dma-map-ops.h>
>  #include <linux/module.h>
>  #include <linux/mm.h>
>  #include <linux/refcount.h>
> @@ -522,6 +523,7 @@ static struct dma_buf *vb2_dma_sg_get_dmabuf(struct vb2_buffer *vb,
>  	exp_info.size = buf->size;
>  	exp_info.flags = flags;
>  	exp_info.priv = buf;
> +	exp_info.coherent = dev_is_dma_coherent(vb->vb2_queue->dev);
>  
>  	if (WARN_ON(!buf->dma_sgt))
>  		return NULL;
> diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> index 41db707e43a4..0b6874733e86 100644
> --- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> +++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> @@ -341,6 +341,7 @@ static struct dma_buf *vb2_vmalloc_get_dmabuf(struct vb2_buffer *vb,
>  	exp_info.size = buf->size;
>  	exp_info.flags = flags;
>  	exp_info.priv = buf;
> +	exp_info.coherent = true;
>  
>  	if (WARN_ON(!buf->vaddr))
>  		return NULL;