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Date:   Wed, 22 Jan 2020 11:53:51 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Hans Verkuil <hverkuil@xs4all.nl>
Cc:     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,
        Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: Re: [RFC][PATCH 02/15] videobuf2: handle V4L2 buffer cache flags
Message-ID: <20200122025351.GF149602@google.com>
References: <20191217032034.54897-1-senozhatsky@chromium.org>
 <20191217032034.54897-3-senozhatsky@chromium.org>
 <ada2381c-2c1c-17c3-c190-48439ae1657a@xs4all.nl>
 <20200122013937.GC149602@google.com>
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On (20/01/22 10:39), Sergey Senozhatsky wrote:
> [..]
> > >  }
> > >  
> > > +static void set_buffer_cache_hints(struct vb2_queue *q,
> > > +				   struct vb2_buffer *vb,
> > > +				   struct v4l2_buffer *b)
> > > +{
> > > +	vb->need_cache_sync_on_prepare = 1;
> > > +
> > > +	if (q->dma_dir != DMA_TO_DEVICE)
> > 
> > What should be done when dma_dir == DMA_BIDIRECTIONAL?
> 

[..]

> We probably cannot enforce any other behavior here. Am I missing
> something?

Never mind. I got your point.

	-ss