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Date:   Sat, 7 Mar 2020 14:26:28 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Hans Verkuil <hverkuil@xs4all.nl>
Cc:     Sergey Senozhatsky <senozhatsky@chromium.org>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Tomasz Figa <tfiga@chromium.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Sakari Ailus <sakari.ailus@iki.fi>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Pawel Osciak <posciak@chromium.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv4 10/11] videobuf2: add begin/end cpu_access callbacks to
 dma-sg
Message-ID: <20200307052628.GB176460@google.com>
References: <20200302041213.27662-1-senozhatsky@chromium.org>
 <20200302041213.27662-11-senozhatsky@chromium.org>
 <f99cd8d2-26a2-acd1-a986-aee66cd2ba12@xs4all.nl>
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On (20/03/06 15:04), Hans Verkuil wrote:
[..]
> > +	/*
> > +	 * NOTE: dma-sg allocates memory using the page allocator directly, so
> > +	 * there is no memory consistency guarantee, hence dma-sg ignores DMA
> > +	 * attributes passed from the upper layer. That means that
> > +	 * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers.
> > +	 */
> >  	buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
> >  				    GFP_KERNEL | __GFP_ZERO);
> >  	if (!buf->pages)
> > @@ -470,6 +476,26 @@ static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
> >  	vb2_dma_sg_put(dbuf->priv);
> >  }
> >  
> > +static int vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
> > +					enum dma_data_direction direction)
> 
> I suggest you use this style to avoid checkpatch warnings:
> 
> static int
> vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
> 				       enum dma_data_direction direction)

OK, will do.

Just for information, my checkpatch doesn't warn me:

$ ./scripts/checkpatch.pl outgoing/0010-videobuf2-add-begin-end-cpu_access-callbacks-to-dma-.patch
total: 0 errors, 0 warnings, 46 lines checked

outgoing/0010-videobuf2-add-begin-end-cpu_access-callbacks-to-dma-.patch has no obvious style problems and is ready for submission.

	-ss