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Subject: Re: [PATCHv13 01/28] v4l2-device.h: always expose mdev
To: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Sakari Ailus <sakari.ailus@iki.fi>
Cc: linux-media@vger.kernel.org, Hans Verkuil <hans.verkuil@cisco.com>
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From: Hans Verkuil <hverkuil@xs4all.nl>
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Date: Tue, 8 May 2018 10:34:29 +0200
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On 05/07/2018 05:46 PM, Mauro Carvalho Chehab wrote:
> Em Fri, 4 May 2018 13:51:28 +0300
> Sakari Ailus <sakari.ailus@iki.fi> escreveu:
> 
>> On Thu, May 03, 2018 at 04:52:51PM +0200, Hans Verkuil wrote:
>>> From: Hans Verkuil <hans.verkuil@cisco.com>
>>>
>>> The mdev field is only present if CONFIG_MEDIA_CONTROLLER is set.
>>> But since we will need to pass the media_device to vb2 and the
>>> control framework it is very convenient to just make this field
>>> available all the time. If CONFIG_MEDIA_CONTROLLER is not set,
>>> then it will just be NULL.
>>>
>>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>  
>>
>> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>>
> 
> This patch is no-brainer. It could be sent no matter what. However,
> the patch is too simple :-)
> 
> There are a number of places where if CONFIG_MEDIA_CONTROLLER
> (and for CONFIG_MEDIA_CONTROLLER_DVB - with is also optionally 
> added at DVB core) is tested just because the field may or may
> not be there.
> 
> If we're willing to always have it at the struct, then we should look
> on all #ifs for CONFIG_MEDIA_CONTROLLER and get rid of most (or all)
> of them, ensuring that function stubs will be enough for the code
> itself to do the right thing if !CONFIG_MEDIA_CONTROLLER.

I looked at this, and in all cases where v4l2_dev->mdev is checked the
following code always uses something that requires CONFIG_MEDIA_CONTROLLER
anyway (usually the entity).

Regards,

	Hans

> 
> Thanks,
> Mauro
>