Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 9 Mar 2020 16:25:26 +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,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [PATCHv4 01/11] videobuf2: add cache management members
Message-ID: <20200309072526.GC46830@google.com>
References: <20200302041213.27662-1-senozhatsky@chromium.org>
 <20200302041213.27662-2-senozhatsky@chromium.org>
 <17060663-9c30-de5e-da58-0c847b93e4d3@xs4all.nl>
 <20200307094634.GB29464@google.com>
 <6f5916dd-63f6-5d19-13f4-edd523205a1f@xs4all.nl>
 <20200307112838.GA125961@google.com>
 <a4d85ac3-0eea-bc19-cd44-0c8f5b71f6bc@xs4all.nl>
 <20200309032707.GA9460@google.com>
 <40cd09d9-49a6-2159-3c50-825732151221@xs4all.nl>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <40cd09d9-49a6-2159-3c50-825732151221@xs4all.nl>
User-Agent: Mutt/1.12.2 (2019-09-21)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On (20/03/09 08:21), Hans Verkuil wrote:
> On 3/9/20 4:27 AM, Sergey Senozhatsky wrote:
> > On (20/03/07 12:47), Hans Verkuil wrote:
> >>
> >> Create those tests in v4l2-compliance: that's where they belong.
> >>
> >> You need these tests:
> >>
> >> For non-MMAP modes:
> >>
> >> 1) test that V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS is never set.
> >>
> >> If V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS is not set, then:
> >>
> >> 1) attempting to use V4L2_FLAG_MEMORY_NON_CONSISTENT will clear the flag
> >>    upon return (test with both reqbufs and create_bufs).
> >> 2) attempting to use V4L2_BUF_FLAG_NO_CACHE_INVALIDATE or V4L2_BUF_FLAG_NO_CACHE_CLEAN
> >>    will clear those flags upon return (do we actually do that in the patch series?).

[..]

> > I'm looking into it. Will it work if I patch the vivid test driver to
> > enable/disable ->allow_cache_hints bit per-node and include the patch
> > into the series. So then v4l2 tests can create some nodes with
> > ->allow_cache_hints.  Something like this:
> 
> I would add a 'cache_hints' module parameter (array of bool) to tell vivid
> whether cache hints should be set or not for each instance. It would be useful
> to have this in vivid. Don't forget to update Documentation/media/v4l-drivers/vivid.rst
> as well.

I see. Hmm, how do I do "test that V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS
is never set" then?

	-ss