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From:   Tomasz Figa <tfiga@chromium.org>
Date:   Mon, 9 Mar 2020 18:17:43 +0900
Message-ID: <CAAFQd5BH2rFZkABej+JfW76f2tjmBBKWm8WjW+TOTBjfewm_9w@mail.gmail.com>
Subject: Re: [PATCHv4 01/11] videobuf2: add cache management members
To:     Sergey Senozhatsky <senozhatsky@chromium.org>
Cc:     Hans Verkuil <hverkuil@xs4all.nl>,
        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>
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On Mon, Mar 9, 2020 at 6:08 PM Sergey Senozhatsky
<senozhatsky@chromium.org> wrote:
>
> 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.

I think that's fine, but we need to make it explicit. :)

Best regards,
Tomasz