Re: [RFC v5 08/11] [media] vb2: add videobuf2 dma-buf fence helpers

From: Alexandre Courbot <acourbot@chromium.org>
To: Gustavo Padovan <gustavo@padovan.org>
Cc: <linux-media@vger.kernel.org>, Hans Verkuil <hverkuil@xs4all.nl>,
	Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
	Shuah Khan <shuahkh@osg.samsung.com>,
	Pawel Osciak <pawel@osciak.com>,
	Sakari Ailus <sakari.ailus@iki.fi>,
	Brian Starkey <brian.starkey@arm.com>,
	Thierry Escande <thierry.escande@collabora.com>,
	<linux-kernel@vger.kernel.org>,
	Javier Martinez Canillas <javier@osg.samsung.com>
Subject: Re: [RFC v5 08/11] [media] vb2: add videobuf2 dma-buf fence helpers
Date: Fri, 17 Nov 2017 16:11:14 +0900	[thread overview]
Message-ID: <71b364e6-967b-4ede-adcc-2c5d4e70af8e@chromium.org> (raw)
In-Reply-To: <a5b0e0e6-4912-4aec-ac6f-f7744a856d3d@chromium.org>

On Friday, November 17, 2017 4:02:56 PM JST, Alexandre Courbot wrote:
> On Thursday, November 16, 2017 2:10:54 AM JST, Gustavo Padovan wrote:
>> From: Javier Martinez Canillas <javier@osg.samsung.com>
>> 
>> Add a videobuf2-fence.h header file that contains different helpers
>> for DMA buffer sharing explicit fence support in videobuf2.
>> 
>> v2:	- use fence context provided by the caller in vb2_fence_alloc()
>> 
>> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> ...
>
> It is probably not a good idea to define that struct here since it will be
> deduplicated for every source file that includes it.
>
> Maybe change it to a simple declaration, and move the definition to
> videobuf2-core.c or a dedicated videobuf2-fence.c file?
>
>> +
>> +static inline struct dma_fence *vb2_fence_alloc(u64 context)
>> +{
>> +	struct dma_fence *vb2_fence = kzalloc(sizeof(*vb2_fence), GFP_KERNEL);
>> + ...
>
> Not sure we gain a lot by having this function static inline, but your call.
>

Looking at the following patch, since it seems that this function is only 
to be
called from vb2_setup_out_fence() anyway, you may as well make it static in
videobuf2-core.c or even inline it in vb2_setup_out_fence() - it would only
add a few extra lines to this function.