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From: Federico Vaga <federico.vaga@gmail.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: 'Mauro Carvalho Chehab' <mchehab@infradead.org>,
	'Pawel Osciak' <pawel@osciak.com>,
	'Hans Verkuil' <hans.verkuil@cisco.com>,
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	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	'Jonathan Corbet' <corbet@lwn.net>
Subject: Re: [PATCH 3/4] videobuf2-dma-streaming: new videobuf2 memory allocator
Date: Thu, 13 Sep 2012 17:46:32 +0200
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> On Thursday, September 13, 2012 3:53 PM Federico Vaga wrote:
> > Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
> 
> A few words explaining why this memory handling module is required or
> beneficial will definitely improve the commit :)

ok, I will write some lines

> > +static void *vb2_dma_streaming_cookie(void *buf_priv)
> > +{
> > +	struct vb2_streaming_buf *buf = buf_priv;
> > +
> > +	return (void *)buf->dma_handle;
> > +}
> 
> Please change this function to:
> 
> static void *vb2_dma_streaming_cookie(void *buf_priv)
> {
> 	struct vb2_streaming_buf *buf = buf_priv;
> 	return &buf->dma_handle;
> }
> 
> and add a following static inline to
> include/media/videobuf2-dma-streaming.h:
> 
> static inline dma_addr_t
> vb2_dma_streaming_plane_paddr(struct vb2_buffer *vb, unsigned int
> plane_no) {
>         dma_addr_t *dma_addr = vb2_plane_cookie(vb, plane_no);
>         return *dma_addr;
> }
> 
> Do not use 'cookie' callback directly in the driver, the driver should
> use the above proxy.
> 
> The &buf->dma_handle workaround is required for some possible
> configurations with 64bit dma addresses, see commit 472af2b05bdefc.

ACK.

-- 
Federico Vaga