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Date:   Mon, 9 Mar 2020 18:08:02 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Tomasz Figa <tfiga@chromium.org>
Cc:     Hans Verkuil <hverkuil@xs4all.nl>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        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 Mailing List <linux-media@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [PATCHv4 01/11] videobuf2: add cache management members
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On (20/03/09 17:58), Tomasz Figa wrote:
[..]
> > > I see. Hmm, how do I do "test that V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS
> > > is never set" then?
> >
> > Not sure I understand your question. When requesting buffers for non-MMAP memory,
> > this capability must never be returned. That has nothing to do with a cache_hints
> > module option.
>
> Have we decided that we explicitly don't want to support this for
> USERPTR memory, even though technically possible and without much
> extra code needed?

My irrelevant 5 cents (sorry), I'd probably prefer to land MMAP
first + test drivers patches + v4l-util patches. The effort
required to land this is getting bigger.

	-ss