linux-kernel - Re: [PATCH] media: vb2: unify calling of set_page_dirty

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Date:   Tue, 10 Oct 2017 10:42:23 +0300
From:   Stanimir Varbanov <stanimir.varbanov@...aro.org>
To:     Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     Stanimir Varbanov <stanimir.varbanov@...aro.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Pawel Osciak <pawel@...iak.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] media: vb2: unify calling of set_page_dirty_lock

Marek,

Any comments?

On 08/29/2017 02:26 PM, Stanimir Varbanov wrote:
> Currently videobuf2-dma-sg checks for dma direction for
> every single page and videobuf2-dc lacks any dma direction
> checks and calls set_page_dirty_lock unconditionally.
> 
> Thus unify and align the invocations of set_page_dirty_lock
> for videobuf2-dc, videobuf2-sg  memory allocators with
> videobuf2-vmalloc, i.e. the pattern used in vmalloc has been
> copied to dc and dma-sg.
> 
> Suggested-by: Marek Szyprowski <m.szyprowski@...sung.com>
> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@...aro.org>
> ---
>  drivers/media/v4l2-core/videobuf2-dma-contig.c | 6 ++++--
>  drivers/media/v4l2-core/videobuf2-dma-sg.c     | 7 +++----
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
> index 9f389f36566d..696e24f9128d 100644
> --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
> +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
> @@ -434,8 +434,10 @@ static void vb2_dc_put_userptr(void *buf_priv)
>  		pages = frame_vector_pages(buf->vec);
>  		/* sgt should exist only if vector contains pages... */
>  		BUG_ON(IS_ERR(pages));
> -		for (i = 0; i < frame_vector_count(buf->vec); i++)
> -			set_page_dirty_lock(pages[i]);
> +		if (buf->dma_dir == DMA_FROM_DEVICE ||
> +		    buf->dma_dir == DMA_BIDIRECTIONAL)
> +			for (i = 0; i < frame_vector_count(buf->vec); i++)
> +				set_page_dirty_lock(pages[i]);
>  		sg_free_table(sgt);
>  		kfree(sgt);
>  	}
> diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
> index 6808231a6bdc..753ed3138dcc 100644
> --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
> +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
> @@ -292,11 +292,10 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
>  	if (buf->vaddr)
>  		vm_unmap_ram(buf->vaddr, buf->num_pages);
>  	sg_free_table(buf->dma_sgt);
> -	while (--i >= 0) {
> -		if (buf->dma_dir == DMA_FROM_DEVICE ||
> -		    buf->dma_dir == DMA_BIDIRECTIONAL)
> +	if (buf->dma_dir == DMA_FROM_DEVICE ||
> +	    buf->dma_dir == DMA_BIDIRECTIONAL)
> +		while (--i >= 0)
>  			set_page_dirty_lock(buf->pages[i]);
> -	}
>  	vb2_destroy_framevec(buf->vec);
>  	kfree(buf);
>  }
> 

-- 
regards,
Stan