Re: [PATCH v5 00/39] i.MX Media Driver

From	Hans Verkuil <hverkuil@xs4all.nl>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 00/39] i.MX Media Driver
Date	2017-03-21 12:10 +0100
Message-ID	<tnpPP-2un-5@gated-at.bofh.it> (permalink)
References	(6 earlier) <tn5Hr-5ly-15@gated-at.bofh.it> <tn60N-5sH-17@gated-at.bofh.it> <tn6ka-5SK-19@gated-at.bofh.it> <tn82B-77f-1@gated-at.bofh.it> <tnpwu-28I-11@gated-at.bofh.it>
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On 03/21/17 11:42, Niklas Söderlund wrote:
> On 2017-03-20 16:57:54 +0100, Hans Verkuil wrote:
>> On 03/20/2017 03:11 PM, Russell King - ARM Linux wrote:
>>> On Mon, Mar 20, 2017 at 02:57:03PM +0100, Hans Verkuil wrote:
>>>> On 03/20/2017 02:29 PM, Russell King - ARM Linux wrote:
>>>>> It's what I have - remember, not everyone is happy to constantly replace
>>>>> their distro packages with random new stuff.
>>>>
>>>> This is a compliance test, which is continuously developed in tandem with
>>>> new kernel versions. If you are working with an upstream kernel, then you
>>>> should also use the corresponding v4l2-compliance test. What's the point
>>>> of using an old one?
>>>>
>>>> I will not support driver developers that use an old version of the
>>>> compliance test, that's a waste of my time.
>>>
>>> The reason that people may _not_ wish to constantly update v4l-utils
>>> is that it changes the libraries installed on their systems.
>>>
>>> So, the solution to that is not to complain about developers not using
>>> the latest version, but instead to de-couple it from the rest of the
>>> package, and provide it as a separate, stand-alone package that doesn't
>>> come with all the extra baggage.
>>>
>>> Now, there's two possible answers to that:
>>>
>>> 1. it depends on the libv4l2 version.  If that's so, then you are
>>>    insisting that people constantly move to the latest libv4l2 because
>>>    of API changes, and those API changes may upset applications they're
>>>    using.  So this isn't really on.
>>>
>>> 2. it doesn't depend on libv4l2 version, in which case there's no reason
>>>    for it to be packaged with v4l-utils.
>>
>> Run configure with --disable-v4l2-compliance-libv4l.
>>
>> This avoids linking with libv4l and allows you to build it stand-alone.
>>
>> Perhaps I should invert this option since in most cases you don't want to
>> run v4l2-compliance with libv4l (it's off by default unless you pass the
>> -w option to v4l2-compliance).
>>
>>>
>>> The reality is that v4l2-compliance links with libv4l2, so I'm not sure
>>> which it is.  What I am sure of is that I don't want to upgrade libv4l2
>>> on an ad-hoc basis, potentially causing issues with applications.
>>>
>>>>>> To test actual streaming you need to provide the -s option.
>>>>>>
>>>>>> Note: v4l2-compliance has been developed for 'regular' video devices,
>>>>>> not MC devices. It may or may not work with the -s option.
>>>>>
>>>>> Right, and it exists to verify that the establised v4l2 API is correctly
>>>>> implemented.  If the v4l2 API is being offered to user applications,
>>>>> then it must be conformant, otherwise it's not offering the v4l2 API.
>>>>> (That's very much a definition statement in itself.)
>>>>>
>>>>> So, are we really going to say MC devices do not offer the v4l2 API to
>>>>> userspace, but something that might work?  We've already seen today
>>>>> one user say that they're not going to use mainline because of the
>>>>> crud surrounding MC.
>>>>>
>>>>
>>>> Actually, my understanding was that he was stuck on the old kernel code.
>>>
>>> Err, sorry, I really don't follow.  Who is "he"?
>>
>> "one user say that they're not going to use mainline because of the
>> crud surrounding MC."
>>
>>>
>>> _I_ was the one who reported the EXPBUF problem.  Your comment makes no
>>> sense.
>>>
>>>> In the case of v4l2-compliance, I never had the time to make it work with
>>>> MC devices. Same for that matter of certain memory to memory devices.
>>>>
>>>> Just like MC devices these too behave differently. They are partially
>>>> supported in v4l2-compliance, but not fully.
>>>
>>> It seems you saying that the API provided by /dev/video* for a MC device
>>> breaks the v4l2-compliance tests?
>>
>> There may be tests in the compliance suite that do not apply for MC devices
>> and for which I never check. The compliance suite was never written with MC
>> devices in mind, and it certainly hasn't been tested much with such devices.
>>
>> It's only very recent that I even got hardware that has MC support...
>>
>> From what I can tell from the feedback I got it seems to be OKish, but I
>> just can't guarantee that the compliance utility is correct for such devices.
>>
>> In particular I doubt the streaming tests (-s, -f, etc.) will work. The -s
>> test *might* work if the pipeline is configured correctly before running
>> v4l2-compliance. I can't imagine that the -f option would work at all since
>> I would expect pipeline validation errors.
> 
> I successfully use v4l2-compliance with the -s option to test the 
> Renesas R-Car Gen3 driver which uses MC, I first have to setup the 
> pipeline using media-ctl. I have had much use of the tool and it have 
> helped me catch many errors in the rcar-vin driver both on Gen2 (no MC 
> involved) and Gen3. And yes the -f option is only usable on Gen2 where 
> MC is not used.

Ah, good to hear that -s works with MC. I was not sure about that.
Thanks for the feedback!

Regards,

	Hans

Thread

Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-18 20:30 +0100
  Re: [PATCH v5 00/39] i.MX Media Driver Steve Longerbeam <steve_longerbeam@mentor.com> - 2017-03-18 21:00 +0100
    Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-18 21:50 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-19 01:50 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 02:10 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 16:00 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-19 16:10 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 11:00 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-19 15:50 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> - 2017-03-19 15:00 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 15:30 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> - 2017-03-19 16:10 +0100
            Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 16:20 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 15:30 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-19 15:50 +0100
    Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 11:50 +0100
      [PATCH 2/4] media: imx: allow bayer pixel formats to be looked up Russell King <rmk+kernel@armlinux.org.uk> - 2017-03-19 11:50 +0100
        Re: [PATCH 2/4] media: imx: allow bayer pixel formats to be looked up Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 23:20 +0100
      [PATCH 1/4] media: imx-media-csi: fix v4l2-compliance check Russell King <rmk+kernel@armlinux.org.uk> - 2017-03-19 11:50 +0100
        Re: [PATCH 1/4] media: imx-media-csi: fix v4l2-compliance check Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 23:20 +0100
      [PATCH 4/4] media: imx-media-capture: add frame sizes/interval  enumeration Russell King <rmk+kernel@armlinux.org.uk> - 2017-03-19 12:00 +0100
        Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval  enumeration Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 23:30 +0100
          Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval  enumeration Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 23:50 +0100
        Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval         enumeration Philippe De Muyter <phdm@macq.eu> - 2017-03-20 10:00 +0100
          Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval  enumeration Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 10:10 +0100
            Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval         enumeration Philippe De Muyter <phdm@macq.eu> - 2017-03-20 10:30 +0100
              Re: [PATCH 4/4] media: imx-media-capture: add frame sizes/interval  enumeration Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 11:50 +0100
      [PATCH 3/4] media: imx-csi: add frame size/interval enumeration Russell King <rmk+kernel@armlinux.org.uk> - 2017-03-19 12:10 +0100
        Re: [PATCH 3/4] media: imx-csi: add frame size/interval enumeration Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 23:30 +0100
        Re: [PATCH 3/4] media: imx-csi: add frame size/interval enumeration Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-22 00:50 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 19:00 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 19:10 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-20 14:10 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 14:40 +0100
            Re: [PATCH v5 00/39] i.MX Media Driver Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-20 15:00 +0100
              Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 15:20 +0100
                Re: [PATCH v5 00/39] i.MX Media Driver Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-20 17:10 +0100
                Re: [PATCH v5 00/39] i.MX Media Driver "Niklas Söderlund" <niklas.soderlund@ragnatech.se> - 2017-03-21 11:50 +0100
                Re: [PATCH v5 00/39] i.MX Media Driver Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-21 12:10 +0100
                Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-21 12:50 +0100
                Re: [PATCH v5 00/39] i.MX Media Driver Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-22 19:20 +0100
    Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 13:20 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-19 20:10 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 21:00 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-19 21:00 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-20 14:00 +0100
      Re: [PATCH v5 00/39] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-03-20 14:30 +0100
        Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 16:50 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-20 17:40 +0100
          Re: [PATCH v5 00/39] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-03-20 17:40 +0100
    Re: [PATCH v5 00/39] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-03-20 14:20 +0100

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