Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit controls from a pipeline

From	Steve Longerbeam <slongerbeam@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit controls from a pipeline
Date	2017-03-03 03:30 +0100
Message-ID	<tgL8J-2LO-9@gated-at.bofh.it> (permalink)
References	<tbjZv-8cO-3@gated-at.bofh.it> <tbjZx-8cO-67@gated-at.bofh.it> <tgC5s-53e-15@gated-at.bofh.it> <tgINA-13L-25@gated-at.bofh.it>
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On 03/02/2017 03:48 PM, Steve Longerbeam wrote:
>
>
> On 03/02/2017 08:02 AM, Sakari Ailus wrote:
>> Hi Steve,
>>
>> On Wed, Feb 15, 2017 at 06:19:16PM -0800, Steve Longerbeam wrote:
>>> v4l2_pipeline_inherit_controls() will add the v4l2 controls from
>>> all subdev entities in a pipeline to a given video device.
>>>
>>> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
>>> ---
>>>  drivers/media/v4l2-core/v4l2-mc.c | 48
>>> +++++++++++++++++++++++++++++++++++++++
>>>  include/media/v4l2-mc.h           | 25 ++++++++++++++++++++
>>>  2 files changed, 73 insertions(+)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-mc.c
>>> b/drivers/media/v4l2-core/v4l2-mc.c
>>> index 303980b..09d4d97 100644
>>> --- a/drivers/media/v4l2-core/v4l2-mc.c
>>> +++ b/drivers/media/v4l2-core/v4l2-mc.c
>>> @@ -22,6 +22,7 @@
>>>  #include <linux/usb.h>
>>>  #include <media/media-device.h>
>>>  #include <media/media-entity.h>
>>> +#include <media/v4l2-ctrls.h>
>>>  #include <media/v4l2-fh.h>
>>>  #include <media/v4l2-mc.h>
>>>  #include <media/v4l2-subdev.h>
>>> @@ -238,6 +239,53 @@ int v4l_vb2q_enable_media_source(struct
>>> vb2_queue *q)
>>>  }
>>>  EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
>>>
>>> +int __v4l2_pipeline_inherit_controls(struct video_device *vfd,
>>> +                     struct media_entity *start_entity)
>>
>> I have a few concerns / questions:
>>
>> - What's the purpose of this patch? Why not to access the sub-device node
>>   directly?
>
>
> I don't really understand what you are trying to say.<snip>
>

Actually I think I understand what you mean now. Yes, the user can
always access a subdev's control directly from its /dev/v4l-subdevXX.
I'm only providing this feature as a convenience to the user, so that
all controls in a pipeline can be accessed from one place, i.e. the
main capture device node.

Steve

Thread

Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-02 17:50 +0100
  Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-03 01:00 +0100
    Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-03 02:00 +0100
    Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-03 03:30 +0100
      Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-03 20:20 +0100
        Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-03 23:50 +0100
  Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-04 00:20 +0100
    Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-04 01:40 +0100
    Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-04 14:20 +0100
      Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-10 14:00 +0100
        Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-10 14:10 +0100
          Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-10 14:30 +0100
            Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-10 15:10 +0100
              Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-10 15:30 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-10 17:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-10 23:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-11 12:30 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-11 23:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-12 00:20 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-12 01:30 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-12 22:30 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-12 23:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-13 13:50 +0100
          Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-10 16:30 +0100
            Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-10 17:00 +0100
              Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-10 18:10 +0100
              Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-10 21:50 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-10 23:00 +0100
        Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-10 16:10 +0100
          Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-11 12:40 +0100
            Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-11 14:20 +0100
              Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-11 16:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-11 18:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-11 19:10 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-11 19:50 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-11 20:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-11 20:10 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-11 20:10 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-11 21:50 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-12 04:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-12 08:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-12 19:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-12 23:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-13 11:50 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-13 12:00 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-13 12:10 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2017-03-13 12:50 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-03-13 13:40 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-12 19:20 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-11 21:30 +0100
                Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-11 21:40 +0100
              Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-03-11 22:40 +0100

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